The invention discloses an embedded electronic equipment software updating method. The method includes the steps that different file catalogs are created under a system of a terminal device for downloading files corresponding to different operations, wherein the file catalogs comprise one or more of ADD, MOD, DEL and SKIP; an updating file information sheet of updating firmware is downloaded from a server side, filenames and verification values in the updating file information sheet are compared with filenames and verification values in an old file information sheet stored in the terminal device, and it is determined that any operation of ADD, MOD, DEL and SKIP is executed; for operations executing ADD or MOD, deviation values and the file length are used as parameters, requests for acquiring corresponding file data are sent to a server, the terminal device receives the file data and then conducts decryption processing on the file data, restores the file data into compressed sack files, and stores the compressed files in the ADD/MOD catalogs; when the updating process is started, the files in the ADD catalog are directly decompressed to the corresponding catalog according to file paths recorded in compressed sacks; old files in the files in the MOD catalog are firstly deleted and then decompression coverage is conducted. According to the software updating method, software updating of the terminal device is faster and safer, the harmful effect of device updating on users is reduced to the maximum degree, and maintenance complexity and maintenance cost of the terminal device are reduced.