The mathematical-economic model of Manjiazhai tin-zinc polymetallic deposit in Dulong town,Maguan city,was established.The ore deposit was delineated by the different cut-off grades,then,the net present value of the ore deposit was calculated,on that basis,the economic evaluation on the ore deposit was made,and the optimal zinc cut-off grade of 3.2% for the deposit was determined.The dynamic production management and the optimization decision and multiple-objective programming of production plan ere achieved in the mining enterprise.In the economic analysis of Manjiazhai tin-zinc polymetallic deposit development,when the cut-off grade of zinc is 0.97%,the most sensitive factor is the price of the mineral products,the cost of the mineral products being the second,the total investment of mine being ten third,while the service life of mine is the least sensitive factor.