In this article, logarithmic spiral curve is successfully applied to bevel gear transmission and used as dentiform line of helicoid bevel gear. Put forward a novel logarithmic spiral bevel gear drive. Because spiral angle on each point of logarithmic spiral curve is constant, the problem of variational spiral angle is solved faultlessly. Analyze the basic characteristics of logarithmic spiral curve and demonstrates the condition of the logarithmic spiral curve used as pitch curve. Put forward the new kind of transmission form of logarithmic spiral bevel gear and it makes up the deficiency in current bevel gear transmission area.