The invention discloses an extend range type electric automobile power system. The extend range type electric automobile power system can solve the problems that a power mass ratio of an existing extend range type electric automobile is inclined to be small, the existing extend range type electric automobile is difficult to arrange and the mass of a finished automobile is uniform in distribution. The extend range type electric automobile power system is composed of a front wheel power sub system, a back wheel power sub system, an energy-storing and power-supplying sub system, an assistant power braking sub system and a vehicle electronic control sub system. The front wheel power sub system comprises a combustion motor, a front axle electric and generating all-in-one machine, a front clutch, a back clutch, a front axle reducer, a front axle differential and a fuel oil system. The back wheel power sub system comprises a drive motor, a back axle reducer and a back axle differential. An output shaft of the drive motor is connected with an input shaft of the back axle reducer in a spline assistant mode. A driven gear of the back axle reducer is fixedly connected with a shell body of the back axle differential. The energy-storing and power-supplying sub system is connected with a high-voltage direct current bus of the finished automobile in a parallel mode. The assistant power braking sub system is connected with the vehicle electronic control sub system in a signal circuit mode. The vehicle electronic control sub system is connected with a controller area network (CAN) bus.