1. A collimation system for a medical apparatus, said collimation system comprising: a collimation component comprising a laser emitting device, at least one photographing device, and a computing device, wherein the laser emitting device is configured to the emit a laser beam to irradiate a landmark on a body surface of a patient, the at least one photographing device is configured to take a photograph of a laser irradiation spot, and the computing device is configured to obtain a target position of the laser irradiation spot by performing computation on images obtained by the at least one photographing device; and a moving component provided on the medical apparatus the moving component configured to be positioned and move to the target position for performing diagnosis or treatment, wherein the medical apparatus automatically is configured to locate the target position based on the position of the irradiation spot obtained from the computation, wherein said laser emitting device comprises a controller configured to control continuous emission of laser pulses and the controller is configured to trigger the at least one photographing device to start taking photographs once the controller starts to continuously emit laser pulses, wherein an acquisition frequency of the at least one photographing device is higher than an emission frequency of the laser pulses.