A vehicle step apparatus including an extending and retracting device having a mounting bracket, a step bracket, and an arm assembly. A gear box has a cavity into which at least a portion of a motor shaft of a motor is inserted. A worm wheel is rotatably disposed in the cavity and has a worm wheel body meshing with the motor shaft. An output shaft is mounted to the worm wheel body. A sun gear is fitted over the output shaft. A planet carrier is rotatably disposed in the cavity and connected with the arm assembly. A planet gear is rotatably mounted to the planet carrier and meshes with the sun gear. An adjusting member is mounted in the gear box, and is movable in an axial direction of the motor shaft and abuts against a free end of the motor shaft.