Some embodiments of the present invention provide an anti-collision device used for a sample-loading system. This device may include a code plate, an optical coupler, a location signal-detecting unit, a drive pulse counting unit and a drive pulse-sending unit. The optical coupler detects the code plate during the relative movement between the optical coupler and the code plate and outputs detection signals. The location signal detecting unit determines whether to output location signals to the drive pulse counting unit. The drive pulse counting unit judges whether collisions occur to the sample-loading system. Some embodiments of the present invention provide an anti-collision method and a sample-loading system comprising the anti-collision device.