The vacuum extractor has been used in many fields in society, especially in health care it plays a important plays in care, treatment as well as emergency aid for patients. However, the usual vacuum extractor has some disadvantages. The machine is enabled when the power is off suddenly: 1/ The pressure it produced is not stable because of the dependence on the machine's structure, the power... 2/ The liquid overflowed will damage the machine or affect the machine's procedures. The creative solution: the new machine is installed additionally the negative pressure bottles with the perfect negative pressure (-760 mmHg) and the adjusted relay. It is named "The negative pressure reservoir machine" which is promulgated the intellectual property certificate (No. 688 dated on 03/03/2008) by the National office of Science and Technology. Results: This new vacuum extractor has fixed the three advantages of the usual machine and helped the doctor feel unworried in treatment, emergency aid for patients. It can also be equipped in the ambulance in emergency aid.