The invention provides a rubber plug system for drilling liner cementing of a horizontal well and relates to the technical field of drilling. The rubber plug system comprises a rubber plug assembly and a pressure-building base; the rubber plug assembly comprises a tail-tube closing rubber plug and a lower rubber plug which are connected with pins, and the tail-tube closing rubber plug is connected with a base pipe of a tail tube running tool by a joint and a connecting sleeve. A ball-tripping device is arranged in an inner hole of the lower rubber plug for capturing ant throwing the ball, building the pressure and carrying out base hanging of a hanger; then, the tail tube is separated, and the rubber plug is closed; an internal sleeve of a two-stage cementing device is adopted for reaching the pressure-building base in a casing collar above a sieve pipe, and locking and sealing are carried out, so as to seal the base and open the two-stage cementing device; the tail-tube closing rubber plug can be locked and sealed with the rubber plug of a drilling pipe, the pressure is built, the base pipe is separated, cement slurry in the tail tube is replaced, and a circulation hole of the two-stage cementing device is permanently closed. The rubber plug system can ensure that the tail tube can smoothly enter into and each set of tool can smoothly realize the functions, thus avoiding the problem that the two-stage cementing device is opened ahead of time or can not be closed and the like and improving the reliability and the efficiency of well cementing.