The invention relates to an automobile rearview mirror with an adjustable viewing angle. The automobile rearview mirror comprises a rearview mechanism and an adjusting mechanism, wherein the rearview mechanism comprises a casing, a motor, a first screw rod, a second screw rod, a fixing unit, a reflector, a support plat, a rotating shaft and a steel wire; the motor, the first screw rod, the second screw rod, the fixing unit, the reflector, the support plat, the rotating shaft and the steel wire are arranged in the casing; the fixing unit comprises sliding blocks, support rods and limiting blocks; and the adjusting mechanism comprises an adjusting rod, a switch, a first belt pulley, a second belt pulley, a third belt pulley, a fourth belt pulley, transmission belts and ratchet components. The automobile rearview mirror with the adjustable viewing angle is elaborate in design and reasonable in structure; after the limiting blocks slide off grooves, the ratchet components on one side are driven to rotate through transmission of the adjusting rod to pull the steel wires, so that the angle of the rearview mirror is adjusted and broader vision is provided for a driver; and the automobile rearview mirror is especially suitable for the situation that an automobile runs from a main road to an auxiliary road or runs from the auxiliary road to the main road, and reduces the accident rate.