In order to solve the problems of long time and low automation for the coupling assemble of optical fiber collimator in production of wavelength division multiplexer, an optical fiber collimator automatic coupling device with five-axis based on Hough circle detection was designed. The five-axis adjusting platform has X, Y and Z moving three degrees of freedom and R and J two rotating degrees of freedom, which was used to drive the U-shaped vacuum suction nozzle for stable suction and pose adjustment of collimator. A vision system was constructed by using semi-transparent infrared light card and camera module. The center coordinates of the spot on the optical card were obtained through Hough circle detection. Furthermore, the collimator was moved to the same axis of the center of the light spot through five-axis adjustment platform to achieve coarse alignment of collimator pose. The collimator was accurately tuned in R and J degrees of freedom to obtain the optimal coupling pose according to the coupled optical power measured by optical power meter for achieving precise coupling of the fiber collimator. The prototype test demonstrate that the efficiency of the automatic coupling device is 6 times higher than that of manual assemble, and the coupling efficiency of optical fiber collimator is larger 75%, which meets the quality requirements of the product. The research provides a reference for efficient automatic coupling of optical fiber collimator.