Abstract: The noise origination of the realtime inspection system in XRay flatpanel detector was analyzed, and the method for removing the stochastic noise was studied. The test image was denoisied through methods of multiframes superimposition and smooth linear and nonlinear filtering. Results indicated that the method had the good effect to eliminate the stochastic noise of actual image, which laid the foundation on the denoising problems in Xray realtime detection process is supplied.