1. A method for pushing information, comprising: pre-processing historical queries on webpages, to obtain a query candidate set; obtaining a specified query input on a webpage; matching the specified query with queries in the query candidate set, the queries in the query candidate set being queries implying a picture; and outputting a corresponding picture on the webpage according to the specified query when there is a query in the query candidate set matching the specified query; wherein the pre-processing historical queries on webpages, to obtain the query candidate set comprises: filtering the historical queries on the webpages according to the numbers of times that the historical queries are input for searching, to obtain a first candidate query set, wherein the number of times that each query in the first candidate query set is input for searching is greater than a first threshold; obtaining a related score of each query in the first candidate query set, and filtering queries in the first candidate query set according to the related score of each query in the first candidate query set, to obtain a second candidate query set; obtaining the number of preset keywords comprised in each query in the second candidate query set, and obtaining a picture implying score of each query in the second candidate query set according to a related score of each query in the second candidate query set and the number of preset keywords comprised in each query; and adding a query, in the second candidate query set, whose picture implying score is greater than a second threshold into the query candidate set; wherein the obtaining a picture implying score of each query in the second candidate query set according to a related score of each query in the second candidate query set and the number of preset keywords comprised in each query comprises: setting a picture implying score of a query in the second candidate query as zero when both a related score of the query and the number of preset keywords comprised in the query are equal to zero; setting a picture implying score of a query in the second candidate query as a seventh threshold when a related score of the query is equal to zero and the number of preset keywords comprised in the query is greater than zero; setting the number of preset keywords comprised in a query in the second candidate query as an eighth threshold when both a related score of the query and the number of preset keywords comprised in the query are greater than zero, and obtaining a picture implying score of the query according to a following formula: the ⁢ ⁢ picture ⁢ ⁢ implying ⁢ ⁢ score ⁢ ⁢ of ⁢ ⁢ the ⁢ ⁢ query = 2 × the ⁢ ⁢ eighth ⁢ ⁢ threshold × the ⁢ ⁢ related ⁢ ⁢ score ⁢ ⁢ of ⁢ ⁢ the ⁢ ⁢ query a ⁢ ⁢ length ⁢ ⁢ of ⁢ ⁢ the ⁢ ⁢ character ⁢ ⁢ string ⁢ ⁢ of ⁢ ⁢ the ⁢ ⁢ query ; and setting the number of preset keywords comprised in a query in the second candidate query as a ninth threshold when a related score of the query is greater than zero and the number of preset keywords comprised in the query is equal to zero, and obtaining a picture implying score of the query according to 2*the ninth threshold*the related score of the query/a length of the query.