This paper presents crosstalk analysis of E-plane multichannel waveguide joints for high frequency. The multi-cavity modeling technique and method of moment are used to analyze the crosstalk. Waveguide has many practical uses in high powered RF systems. When two channel waveguides are joined, the phenomenon of crosstalk will certainly appear, and the reason behind is poor workmanship. The gap appearing at the flange joint causes power coupling to the neighboring ports. In this paper two channel E-plane waveguide joints for frequency range 15 GHz to 18 GHz have been analyzed. Scattering parameters data obtained from cavity model analysis have been verified and compared with CST microwave studio simulated and measured data.