Abstract: The domestic microwave oven is not suitable for further needs of chemical research. Fitted with a length of cur-off waveguide and a chok system onto the walls of a microwaveoven so as to install a reflux tube and stirrer .it is proved that the modified microwave oven is suitable for chemical synthesis. The microwave leakage of the modified oven is less than 1mW/cm2.Some results of chemical synthesis conducted in the oven is also reported,which shows the accelerated effects of microwave on the chemical synthesis.