Aimed at the problems that battlefield environments are complex, reconnaissance party is difficult to obtain complete information of target emitter, and the traditional radiation source threat assessment algorithms are not suitable for the case of data loss, an Induction Ordered Weighted Average operator null value estimation algorithm is introduced in combination with Technique for Order Preference by similarity to an Ideal Solution method weighted by CV correctionG1 method to construct the radiator threat assessment model based on IOWATOPSIS under conditions of missing data. Firstly, IOWA operator is utilized for estimating the null value to solve the problem of incomplete data. Then, the improved G1 method based on coefficient of variation method is used to realize the combination weight of each attribute. Finally, the threat degree of radiation sources is sorted by TOPSIS algorithm. The effectiveness of the algorithm is verified by simulation. The method expands the application range of TOPSIS algorithm, and realizes the emitter threat assessment in the case of missing data.