Provided are a method and apparatus for determining a blockage of a filter of a clothes dryer and a clothes dryer. The clothes dryer includes a motor. The method includes following steps. An actual rotational speed of the motor is acquired, and an electrical parameter corresponding to a rotational speed range to which the actual rotational speed belongs is determined as a first threshold corresponding to the actual rotational speed; an actual clothes volume in the clothes dryer is acquired, and the first threshold is corrected according to a correction coefficient corresponding to a clothes volume range to which the actual clothes volume belongs so that a second threshold is obtained; and an actual electrical parameter of the motor is acquired, and when it is detected that the actual electrical parameter is less than the second threshold, it is determined that the filter of the clothes dryer is blocked.