A computer-implemented method for similar character string search in a candidate character string set, the method comprising: obtaining an association bitmap information of a candidate character string of the candidate character string set and a given target character string, wherein the association bitmap information comprises bitmap weights of two character string bitmaps corresponding to the candidate character string and the target character string; screening out the candidate character string if the difference between a bitmap weight of the character string bitmap corresponding to the candidate character string and a bitmap weight of the character string bitmap corresponding to the target character string is greater than a distance threshold, otherwise obtaining a bitmap weight of a bitmap difference between two character string bitmaps corresponding to the candidate character string and the target character string, and screening out the candidate character string if the bitmap weight of the bitmap difference between the two character string bitmaps is greater than the distance threshold; wherein the character string bitmap comprises a plurality of flag bits, a value of the flag bit comprises a first value and a second value, the first value indicating that a predetermined standard character corresponding to the flag bit is comprised in a character string, and the second value indicating that a predetermined standard character corresponding to the flag bit is not comprised in the character string, the bitmap weight of the character string bitmap indicates the number of first values in the character string bitmap, the bitmap difference is obtained by performing an exclusive OR operation on a value of each flag bit in the target character string bitmap and a value of a corresponding flag bit in the candidate character string bitmap, and the bitmap weight of the bitmap difference indicates the number of flag bits whose exclusive OR values are true in the bitmap difference; calculating a character string distance between each remaining candidate character string and the target character string; and selecting a character string based on the character string distance between each remaining candidate character string and the target character string. obtaining an association bitmap information of a candidate character string of the candidate character string set and a given target character string, wherein the association bitmap information comprises bitmap weights of two character string bitmaps corresponding to the candidate character string and the target character string; screening out the candidate character string if the difference between a bitmap weight of the character string bitmap corresponding to the candidate character string and a bitmap weight of the character string bitmap corresponding to the target character string is greater than a distance threshold, otherwise obtaining a bitmap weight of a bitmap difference between two character string bitmaps corresponding to the candidate character string and the target character string, and screening out the candidate character string if the bitmap weight of the bitmap difference between the two character string bitmaps is greater than the distance threshold; wherein the character string bitmap comprises a plurality of flag bits, a value of the flag bit comprises a first value and a second value, the first value indicating that a predetermined standard character corresponding to the flag bit is comprised in a character string, and the second value indicating that a predetermined standard character corresponding to the flag bit is not comprised in the character string, the bitmap weight of the character string bitmap indicates the number of first values in the character string bitmap, the bitmap difference is obtained by performing an exclusive OR operation on a value of each flag bit in the target character string bitmap and a value of a corresponding flag bit in the candidate character string bitmap, and the bitmap weight of the bitmap difference indicates the number of flag bits whose exclusive OR values are true in the bitmap difference; the character string bitmap comprises a plurality of flag bits, a value of the flag bit comprises a first value and a second value, the first value indicating that a predetermined standard character corresponding to the flag bit is comprised in a character string, and the second value indicating that a predetermined standard character corresponding to the flag bit is not comprised in the character string, the bitmap weight of the character string bitmap indicates the number of first values in the character string bitmap, the bitmap difference is obtained by performing an exclusive OR operation on a value of each flag bit in the target character string bitmap and a value of a corresponding flag bit in the candidate character string bitmap, and the bitmap weight of the bitmap difference indicates the number of flag bits whose exclusive OR values are true in the bitmap difference; calculating a character string distance between each remaining candidate character string and the target character string; and selecting a character string based on the character string distance between each remaining candidate character string and the target character string.