To　solve　the　problem　of　inaccuracy　and　unconvenience　of　the　traditional　camera　calibration,　a　new　arithmetic　was　put　forward.　An　equation　group　about　the　five　inner　parameters　of　the　camera　was　educed　based　on　the　fundamental　matrix　equation.　The　translations　along　the　x　axis　and　the　z　axis　have　been　obtained,　and　five　inner　parameters　have　been　calculated.　The　simulated　experiments　have　proved　that　the　arithmetic　has　high　degrees　of　accuracy.