Development and application of pseudo-random code combined fuze can be guided in theory by researching its anti-jamming performance. The anti-noise FM jamming performance of pseudo-random code phase modulation and sine FM combined fuze is analyzed based on the criterion of signal to jamming ratioin (SJR) gain in this paper. First, the principle of the combined fuze was introduced, and its overall SJR gain is reduced in detail under the noise FM jamming, then, the factors affecting its anti-noise FM jamming performance were analyzed, such as the nth order Bessel function of the first kind, Doppler frequency, pseudo-random code period, pulse width, and spot error. The results provide the important theoretic foundation for the improvement on anti-noise FM jamming performance of the combined fuze. At the same time, the studying method put forward in this paper may be used as the reference for analyzing anti-jamming performance of other type of fuzes.