A braking pedal feel simulating device of an automobile brake-by-wire system comprises a braking pedal, a pedal controlling arm, a pedal shaft, a pedal fixing support, a torsion spring, a pedal angle displacement sensor, a pedal force sensor and a pedal feel simulator. The braking pedal is fixedly connected with the pedal controlling arm, a round hole is processed at the upper end of the pedal controlling arm which is rotatably connected with the pedal shaft, the pedal shaft is mounted in a mounting hole of the pedal fixing support, a guide small hole is formed in the pedal fixing support, the diameter of the guide small hole is in interference fit with the outer diameter of a pushing rod, the torsion spring is cylindrical and is sleeved on the pedal shaft in a hollow manner, one end of the torsion spring is fixedly connected on the pedal fixing support while the other end of the same is connected on the pedal controlling arm, the torsion spring reverses and generates spring force along with rotating of the pedal controlling arm, the pedal angle displacement sensor is mounted in the round hole at the upper end of the pedal controlling arm, the pedal force sensor is mounted on the braking pedal, and the front end of a pushing rod of the pedal feed simulator is rotatably connected with the pedal controlling arm.