The invention discloses a multipath continuous data acquisition device of a two-channel microwave density and humidity detector. The device comprises an A/D converting circuit, a data buffer circuit, a microprocessor, an external interface circuit, a programming logic device, a work state indicating lamp and a host computer and the above units are orderly connected. The programming logic device is respectively connected to the A/D converting circuit, the data buffer circuit, the microprocessor and the external interface circuit. The microprocessor is connected to the host computer through a RS232 interface and is connected to a cigarette making and plug assembling machine through a CAN interface. The programming logic device is connected to the cigarette making and plug assembling machine through a RS485 interface. The invention also provides a data acquisition method using the multipath continuous data acquisition device. The method comprises receiving a signal of the cigarette making and plug assembling machine through the programming logic device, controlling all circuits and producing an interrupt signal through the programming logic device, determining the interrupt signal through the microprocessor, reading the A/D sample data and carrying out computation through the microprocessor, uploading the computation result to the cigarette making and plug assembling machine and after an interrupt revocation signal is received, carrying out secondary data acquisition computation. The device and method realize real-time high-efficiency continuous sampling and computation.