A distance measurement method is provided that includes the steps of transmitting a laser signal to a target, receiving outside signals reflected by the target, converting the outside signals into an analog voltage signal, sampling the analogy voltage signal to obtain digital signals, storing the digital signals at storage addresses in a one-to-one relationship, repeating the above steps, accumulating numeral values at each storage addresses to obtain an accumulated value, outputting the accumulating value which exceeds a constant and corresponds to a time point, and calculating the distance between a laser range finding device and the target according to the time point corresponding to the output accumulated value.