For solving the uneven cooling problem of VAV (variable air volume) air conditioning operation, two kinds of variable static pressure and one kind of constant pressure control strategies of VAV system were operated. The relationship of room temperature,air volume,fan frequency,maximum value position,and setting pressure valve with fan power consumption respectively were analyzed and compared. Experimental results show that in addition to the set temperature, the Indoor Aai Quality(IAQ)、relative humidity and other factors should be considered in the design of valve control algorithm for variable air volume box; When using the variable air volume air conditioning system, the room temperature should be reduced to the set temperature, then the automatic control system is opened to avoid being affected by the delay of the algorithm. As to transporting unit cooling load, the electrical consumption under constant static strategy is more 7.8% than it under variable pressure strategy which static pressure measuring point is nearing the fan. And the cooling effect of constant static strategy is poor. Under the same outside conditions, compared to variable pressure strategy with static pressure measuring point nearing the fan, the cooling effect under the variable pressure strategy with static pressure measurement point far away from the fan is better. The cooling rate is at least 14% faster. And the consumption of electricity is almost the same.