A laser protection system includes a high-power laser source, an optical diffuser, a photo detector, a signal-processing device, and a control module. The high-power laser source generates a first laser light beam, and the optical diffuser attenuates a laser power of the first laser light beam to form a second laser light beam. The photo detector obtains an optical detection signal from the second laser light beam. The signal-processing device includes a signal conversion module, a processor, and an encoder. The signal conversion module transforms the optical detection signal into a measurement data eigenvalue. The encoder encodes the measurement data eigenvalue into a measured encoded data, and the setting data eigenvalue into a set encoded data. The control module evaluates the set encoded data and the measured encoded data to determine whether or not the high-power laser source needs to be stopped.