Provided is a method for measuring the heights of components based on laser ranging, including the following steps of: 1) a laser ranger uniformly moving along a test route and measuring the distance from each test point to the laser ranger; 2) the laser ranger transmitting the measurement result and the measurement time to a storage unit; 3) the storage unit sending the received measurement result and the received measurement time to an analysis unit; and 4) according to the data sent by the storage unit and referring to the test route and the position of each test point, the analysis unit calculating the height of each test point and outputting it. The method of the present invention omits the time of determining the position of each point and the start-stop time of the laser ranger at each test point so that saving the large amount of the measurement time.