In order to solve the problem of color inconsistency between the projection pictures of various projectors in a multi-channel projection display system, a multi-projection color correction method based on free-form deformation technology was designed. Firstly, the free-form deformation model was established by Bernstein basis function, and the color conversion relationship between the original image of each projector and the image taken by the camera was established. Then, collected the original image set and the projection display picture set taken by the camera to determine the parameters of the free-form deformation technology model. Moreover, through Matlab analysis, it was verified that each color channel of projection image was affected by each other. Finally, the original image was color distorted, and the proposed color correction method was compared with the traditional method for histogram similarity evaluation. The experimental results show that, compared with the generalized color correction method and the color correction method based on B-spline curve, the proposed method reduces the average difference of color intensity of the projected image by 2.50 in the B channel, 2.34 in the G channel, and 3.57 in the R channel. The correlation of histogram is increased by 8.9%, and the Pap distance is reduced by 9.7%.The multi-projection color correction method based on free-form deformation makes the projection images smoothly connected, and brings the user a better immersion experience.