Influence of collimation mismatch angle on laser heterodyne detection mixing efficiency is studied under the conditions of local beam optical field distribution as Gaussian distribution and signal beam optical field distribution as Airy function.The advantages and disadvantages of receiving optical system based on Airy disk principle in decreasing the influence of collimation mismatch on mixing efficiency are analyzed.In addition，a new method called array detectors matching receiving method is put forward，which effectively decreases the influence of collimation mismatch angle on mixing efficiency.Result shows this method can effectively improve the mixing efficiency and current output when collimation mismatch angle exists.By this method heterodyne detection under the condition of big collimation mismatch angle can be implemented.Furthermore，this method has wide receiving field of view.