A stirrer with positive pressure automatic charging system is characterized in that powder enters a filter from a charging pipe by opening a regulator valve of the charging pipe by a PLC, the powder enters a powder conveying bin after being filtered by a filter cylinder in the filter and then enters the stirrer by a conveying pipe, excessive gas in the stirrer is exhausted by an exhausting pipe, when filter slag in the filter is too much, gas exhausting in the filter cylinder is affected, air pressure in the filter cylinder is increased, when the air pressure in the filter cylinder is larger than set air pressure of an air pressure gauge, the regulator valve of the charging pipe is controlled by the PLC to be closed, so as to reduce the air pressure of the filter cylinder; after gas is conveyed by a monitoring pipe for a short time, a regulator valve of the monitoring pipe is closed, a regulator valve of the conveying pipe is closed, a regulator valve of a slag discharging pipe is opened, then a regulator valve of an inlet air pipe is opened, so that the filter slag is discharged out of the filter cylinder by high pressure air.