To achieve software output domain coverage is a challenge to the functional testing of security-critical software. This paper proposed a test data generation method based on artificial immune algorithm using intelligence testing approach. Firstly, based on the analysis of the software output domain coverage problem, we gave the basic idea of applying artificial immune algorithm to software testing, and introduced the general steps of the algorithm. Secondly, we designed the main operators of the artificial immune algorithm, such as antibody affinity evaluation operator, antibody concentration evaluation operator, immune selection operator, clone operator, mutation operator, etc., to achieve the automatic generation of software test data. Finally, several software was used to verify the validity of the method. The verification results show that the method achieves the software output domain coverage, and its effect is better than the genetic algorithm and random testing.