The invention discloses a distributed pipeline monitoring device and method based on wavelength division and time division joint multiplexing. The device comprises a first light source, a second lightsource, a first optical switch, a second optical switch, a first coupler, a delay optical fiber, a connecting optical fiber, a second coupler, a first wavelength division multiplexer, an optical circulator, an optical fiber sensing array, a second wavelength division multiplexer, a first photodetector, a second photodetector, a multi-channel high-speed data acquisition card, a digital signal processing card and an industrial control computer; the vibration information of a pipeline is obtained through a phase sensitive optical time domain reflection principle-based distributed optical fiber vibration sensing array; the pressure information of the pipeline is obtained through an optical wavelength modulation principle-based fiber grating strain sensing array; and the distributed optical fiber vibration sensing array and the fiber grating strain sensing array share the same optical fiber to realize transmission and work based on a wavelength division multiplexing and time division multiplexing mechanism. According to the device, pipeline vibration information monitoring and stress information monitoring are well balanced, system integration is high, and the leakage and security warning accuracy of the pipeline monitoring system can be improved; and transmission optical fiber length required by the device is same as optical fiber length required by a single function sensing device, and therefore, the utilization rate of transmission optical fibers can be improved, and costs can be greatly reduced.