A device capable of quickly adjusting continuous variable entanglement source signal light interference comprises a laser device, a first optical parameter cavity, a second optical parameter cavity, afirst beam splitting unit and a second beam splitting unit and also comprises a first auxiliary light unit, a second auxiliary light unit, a first dichroic mirror, a second dichroic mirror and a third dichroic mirror. By switching mode matching for adjusting output signal light beams in the optical parameter cavities into mode matching for adjusting pumping light beams, weak signal light interference adjustment uneasy to observe is converted into higher-light-intensity frequency doubling light interference adjustment, and the device has the advantages of being accurate, convenient and visualin adjustment and the like; a light path for interference adjustment completely utilizes the existing light path producing entanglement light in the device, and introduction of an additional new laserelement is not needed, so that the device is simple in structure and low in cost; the output signal light in the two optical parameter cavities are reshaped into parallel light by utilizing an auxiliary light path, so that signal light is more convenient to transmit and reshape in space.