Camera calibration is a very important part in machine-vision-system research. To calibrate a camera better and faster, we propose a camera-parameter-optimization method based on hybrid particle-swarm optimization. First, we obtain the internal and external parameters of the camera by the least-squares method and use them as the initial values of the parameters to be optimized. Then, we establish the objective function using the minimum-distance criterion. Next, we use a hybrid particle-swarm optimization algorithm to further optimize the camera parameters, and finally we obtain the camera parameters with only small errors. Our experimental results show that the optimization algorithm can converge quickly and accurately. Therefore, this method is able to improve camera-calibration accuracy of the camera to some extent.