Online filter membrane integrity testing device and method and application thereof

The invention provides an online filter membrane integrity testing device and method and application, the online filter membrane integrity testing device is used for online filter membrane integrity testing in radioactive liquid medicine production, and the online filter membrane integrity testing device comprises a double-communication-port filter which is detachably arranged on a radioactive liquid medicine production line and comprises a first communication port, a second communication port and a third communication port, the radioactive liquid medicine or the pressurized gas is introduced into the double-communication-port filter; the second communication port is communicated with the first communication port; the outlet is configured to discharge the radioactive liquid medicine or the pressurized gas from the double-communicating-port filter, the gas filter is connected with the second communicating port through the communicating pipe, a switch valve is arranged on the communicating pipe, and the switch