The invention discloses a method for rapidly updating a television program of a single-tuner set top box, relating to a digital television set top box technology and aiming at providing a method for realizing that a program updating process is automatically completed in background without influencing watching programs by a user when the television program of the single-tuner set top box is updated. The method is characterized by comprising the steps of: obtaining NIT (Network Information Table) and SDT (Service Description Table) data from a main frequency point by the set top box, when programs are updated, obtaining frequency point lists, program numbers, program names and other information of all programs from the NIT and SDT table data, establishing a temporary program database B, setting audio and video PID (Process Identification) information of each program in the program database B to be NULL, and when the program selected by the user in the audio and video PID information in the program database B is inconsistent with the information stored in the original system, capturing PAT (Program Associated Table) and PMT (Program Map Table) data sheets of the current frequency point so that audio and video PID information of all programs of the current frequency point is obtained. The invention is mainly used in the single-tuner digital television set top box.