1. 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 word matching algorithm is as follows: S 1 = ∑ i = 1 m ⁢ ⁢ ( qtf i k 3 + qtf i ) × ( ( k 1 + 1 ) × tf i k × ( 1 - b + b ⁢ ⁢ l avdl ) + tf i ) ⁢ log ⁡ ( w i ) wherein k 1 , k 3 , k and b are constants, qtf i is the word frequency of the i th vector t i in the information to be searched, tf i is the word frequency of the vector t i in a corresponding relevant document, l is the length of the corresponding relevant document, avdl is the average length of all obtained relevant documents, and w i is the weight of the vector t i .