The present invention provides a pulsed neutron generator. In a high vacuum and high pressure ceramic tube, when a trigger pulse is added between the source trigger pole and cathode of vacuum arc ion, the deuterium atom is ionized and the initial plasma is diffused, such that the anode and the cathode of the ion source is conducted, the arc current is formed, and the high density plasma is generated. Under the action of accelerating the high pressure, the deuterium ion beam interacts with the tritium titanium target, the deuterium tritium reaction produces, and the pulsed neutron with the energy of 14 MeV is generated. A circular magnetic field is set up at the lead pole of the vacuum arc ion source, which can focus on the formation of the deuterium ion, increase the deuterium ion beam to the target, improve the pulsed neutron yield; The combination of a dry pump, a molecular pump, an ion pump and an air pump is used to improve the vacuum degree of the system, and reduce the loss of deuterium ion beam in the transmission process. The aluminum film with the thickness of 400 nm is coated on the surface of the tritium titanium target, which prevents the heavy ion from reaching the tritium target, and reduces the damage of the target.