An abnormality detection device includes: a torque upper limit setting module that sets an upper limit of torque based on an allowable input torque for the continuously variable transmission, the upper limit of torque limiting an output torque of an engine; a determination torque calculation module that determines an acceleration requested by a driver based on an amount of operation of an accelerator, obtains a running resistance of a vehicle according to the requested acceleration, and calculates a determination torque for determining abnormality of the upper limit of torque based on the running resistance of the vehicle and a gear ratio of the continuously variable transmission; and an abnormality determination module that determines the upper limit of torque to be abnormal in the case where the upper limit of torque is less than or equal to the determination torque.