The invention discloses a vacuum sealing dewar for an EMCCD (Electron Multiplying Charge Coupled Devices) detector. The vacuum sealing dewar for the EMCCD detector is formed by a semiconductor cooler,a glass window, a kovar upper case, a kovar base, an EMCCD, an anti-glare screen, a getter, a copper heat radiation base and an electrode lead. The glass window and the kovar upper case are welded through indium seal; the copper heat radiation base and the kovar base adopt brazing; the electrode lead and the base adopt glass sealing; devices are cleaned, baked at high temperature, and degassed soas to be assembled on the kovar base; the kovar upper case and the base are placed in a vacuum chamber and are separated from each other at a certain distance, and the vacuum chamber is vacuumized and exhausted for a certain time; and after exhausting, an upper cover and the base are welded through laser welding. The dewar has the advantages of simple structure and low leak rate, and is applicable to vacuum sealing a cooling type scientific grade CCD detector.