Along with the increasing electric load in the mobile, the request of the mobile electric system is increasing as well. Today, the standard output voltage of the claw alternator in the mobile is 12V or 24V. The performance and efficiency of the traditional claw alternator in the mobile cannot meet with the increasing request of them anymore. In addition to actively develop the new claw-pole alternator, try hard to improve the performance and efficiency of the traditional motor by optimizing the parameters is a solution to the problem of efficient and economic means. This paper will calculate the basic mathematical claw alternator model of the 14V machine. Based on it, have the machine’s structural parameters analyzed and optimized, making the operating performance as high as possible on the basic size of the motor in the original.