4. A search method, comprising: obtaining relevant documents of information to be searched; calculating a correlation between each obtained relevant document and the information to be searched, based on a word matching algorithm and a semantic matching algorithm; and sorting the obtained relevant documents according to the calculated correlation, and displaying a sorting result; wherein said calculating a correlation between each obtained relevant document and the information to be searched based on a word matching algorithm and a semantic matching algorithm comprises: vectorizing the information to be searched, to obtain m vectors t i , wherein m and i are both positive integers, and 1≦i≦m; vectorizing each obtained relevant document, to obtain n vectors d j corresponding to each relevant document, wherein n and j are both positive integers, and 1≦j≦n; calculating a relevancy score S 1 of each relevant document to the information to be searched based on the word matching algorithm, and calculating a relevancy score S 2 of each relevant document to the information to be searched based on the semantic matching algorithm; calculating the correlation S between each relevant document and the information to be searched, according to the formula of S=α×S 1 +(1−α)×S 2 , wherein α is a preset weight, and 0<α<1; wherein the formula of the semantic matching algorithm is as follows: S 2 = ∑ i = 1 m ⁢ ⁢ ∑ j n ⁢ ⁢ 1 k 3 + 1 × ( k 1 + 1 k × ( 1 - b + b ⁢ ⁢ l avdl ) ) ⁢ mi ⁡ ( t i , d j ) wherein k 1 , k 3 , k and b are constants, l is the length of a corresponding relevant document, avdl is the average length of all the obtained relevant documents, and mi(t i ,d j ) is the mutual information between the vector t i and the vector d j .
4. A search method, comprising: obtaining relevant documents of information to be searched; calculating a correlation between each obtained relevant document and the information to be searched, based on a word matching algorithm and a semantic matching algorithm; and sorting the obtained relevant documents according to the calculated correlation, and displaying a sorting result; wherein said calculating a correlation between each obtained relevant document and the information to be searched based on a word matching algorithm and a semantic matching algorithm comprises: vectorizing the information to be searched, to obtain m vectors t i , wherein m and i are both positive integers, and 1≦i≦m; vectorizing each obtained relevant document, to obtain n vectors d j corresponding to each relevant document, wherein n and j are both positive integers, and 1≦j≦n; calculating a relevancy score S 1 of each relevant document to the information to be searched based on the word matching algorithm, and calculating a relevancy score S 2 of each relevant document to the information to be searched based on the semantic matching algorithm; calculating the correlation S between each relevant document and the information to be searched, according to the formula of S=α×S 1 +(1−α)×S 2 , wherein α is a preset weight, and 0<α<1; wherein the formula of the semantic matching algorithm is as follows: S 2 = ∑ i = 1 m ⁢ ⁢ ∑ j n ⁢ ⁢ 1 k 3 + 1 × ( k 1 + 1 k × ( 1 - b + b ⁢ ⁢ l avdl ) ) ⁢ mi ⁡ ( t i , d j ) wherein k 1 , k 3 , k and b are constants, l is the length of a corresponding relevant document, avdl is the average length of all the obtained relevant documents, and mi(t i ,d j ) is the mutual information between the vector t i and the vector d j . 5. The method according to claim 4 , wherein the calculation formula of the mutual information between the vector t i and the vector d j is as follows: mi ⁡ ( t i , d j ) = log ⁢ ⁢ p ⁡ ( t i , d j ) p ⁡ ( t i ) ⁢ p ⁡ ( d j ) wherein p ⁡ ( t i , d j ) = c ⁡ ( t i , d j ) ∑ t i ⁢ d j ⁢ ⁢ c ⁡ ( t i , d j ) , c(t i ,d j ) represents the number of times the vector t i and the vector d j appear in the same document at the same time in network; p ⁡ ( t i ) = c ⁡ ( t i ) ∑ t i ⁢ ⁢ c ⁡ ( t i ) , c(t i ) represents the number of times the vector t i appears in the network; p ⁡ ( d j ) = c ⁡ ( d j ) ∑ d j ⁢ ⁢ c ⁡ ( d j ) , c(d j ) represents the number of times the vector d j appears in the network.