Due to the non-Newtonian characteristics of fluid in heavy oil reservoir during cold production，conventional methods cannot be used in precisely predicting horizontal wells productivity when its dynamic production characteristic is different from that of conventional oil wells. During the cold production，the rheological behavior of heavy oil can be assumed as Bingham type. According to the percolation features of cold production in heavy oil reservoirs，threshold pressure gradient was taken into consideration. Then the seepage filed of the horizontal well was divided into inner and outer two parts while the productivity formulas were derived respectively. In addition，moving radius was obtained by the average pressure derivative method. Based on the equivalent principle of flow rates for both regions，nonlinear equations regarding to the horizontal well production rate and the moving radius were established. Eventually，the values of the oil production rate and moving radius under arbitrary time were acquired by Newton-Raphson method. Numerical results from a case manifest that the production performances of the well by cold production in the heavy oil reservoir can be characterized by high initial production，rapid decline and relatively long period of stabilized production，which can provide theoretical foundation for oil production forecast and later optimization adjustment. Sensitivity analysis results show that longer horizontal section length and larger reservoir thickness bring higher production during the same production time. And lower threshold pressure gradient and lower oil viscosity bring higher production.