本文的目的是揭示引力场和电磁场的相互作用。第一部分由作用量原理出发,统一地建立了弓:力场和电磁场的复合场方程组;第=部分由所建立的方程组,讨论了一个有兴趣的问题——带电质量线的复合场,揭示两种场的相互作用;第三部分证明了电磁场激发的引力场以真空中的光速传播;最后指出了光子可以衰变为引力子以及由此产生的红穆效应。 The purpose of this paper is to reveal the interaction of gravitational and electromagnetic fields. In the first part, based on the principle of action, a set of complex field equations of force field and electromagnetic field are established uniformly. In the second part, an interesting problem is discussed based on the established equations. The complex field of charged mass line, The third part shows that the gravitational field excited by the electromagnetic field propagates at the speed of light in vacuum. Finally, we point out that the photons can decay into gravitons and the red-light effect.