In order to make a reasonable verification on the condition of small samples of airborne fire control radar detection range index, and save the cost of test, based on the analysis of the commonly used evaluation method of radar detection range is insufficient, according to characteristics of radar detection distance test, put forward using t distribution theory in mathematical statistics, according to the radar detection range was estimated t distribution method, radar detection distance distribution with t distribution center, while the test sample is predicted. The radar detection distance of small sample t distribution test method, which can reduce flight test vehicles, test results are credible. Practice has proved that the method has obvious advantages and application prospects.