To comprehensively evaluate the detection capability of the laser fixed-distance fuze, and obtain the variation in detection capability with the detection distance, the analytic equation of the distribution of pulsed laser ranging was established by deriving the echo equation of pulsed laser ranging, and an error quantification evaluation method was also proposed. The influence of detection distance on echo signal and the indicators of detection capability were analyzed and evaluated, and the results were verified by experiments. Results indicate that the detection of fuze is reliable within its reliable range. In addition, the random ranging error tends to initially decreases and then increases while the system error has the trend to increase gradually as the detection distance decrease. The maximum reliable range of fuze is 84.8 m and the random error is 0.22-0.73 m in the reliable range, thus satisfying the requirement of remote fixed-distance fuze. Besides, with the increase of the threshold, the range error can be obviously improved a lot, although the reliable range is caused to be reduced. The variation rules and evaluation methods in this work can provide a theoretical basis for the design and application of the pulsed laser fuze.