1. A method for searching for a contact object, comprising: normalizing, by a terminal comprising at least a processor and a memory, contents of contact fields contained in contact objects stored in the memory of the terminal; receiving an input string for contact object searching from a user interface displayed by the terminal; normalizing the input string; searching in the normalized contents of the contact fields according to the normalized input string, to obtain a matching field; acquiring information of a contact object containing the matching field as a contact searching result; and displaying, by the processor, the input string and the contact searching result on the user interface; wherein normalizing contents of contact fields further comprises: for a first contact field, obtaining a first string corresponding to a content of the first contact field, the first string being formed by characters contained in a full keyboard, wherein the first string includes multiple alphabet characters; obtaining a second string corresponding to the same content of the first contact field by mapping alphabet characters in the first string to digits according to a designated mapping relation, wherein the designated mapping relation assigns each alphabet character with a single corresponding digit the second string includes multiple digits corresponding to the multiple alphabet characters; and when the first string further includes a non-alphabet character, the non-alphabet character is unchanged in the second string; and incorporating both the first string and the second string into the normalized contents of the contact fields as corresponding strings for the first contact field, wherein searching in the normalized contents of the contact fields according to the normalized input string further comprises: respectively matching the first string and the second string with the normalized input string; and when either one of the first string or the second string matches with the normalized input string, determining the first content field as the matching field, such that the first content field can be matched regardless of whether a user input is a digit combination or an alphabet combination.