Abstract: According to the turbulence model theory foundation and its application scope, based on microscale, this paper analyzes the viscosity dissipation of turbulence. Continuity equation, momentum equation and energy equation are used to construct Reynold turbulence flow model. According to the Prandtl mixing length theory, this paper constructs pulsation and averaging differential equation and confirms the relations of heat convection Nu and specific heat, fluid temperature, frictional factor to deduce the calculation formula.