The invention belongs to the technical field of electronic components, and provides a water-proof and damp-proof temperature sensor, which includes a thermosensitive chip placed in a casing and a connector placed at the outer part of the casing, wherein the thermosensitive chip and the connector are connected through PVC sheathed lines; the thermosensitive chip is provided with three silica gel sealing layers; the thermosensitive chip is wrapped with the first silica gel sealing layer in a sealing manner, and then is wrapped, sealed and solidified by epoxy encapsulating material; the thermosensitive chip, pins and welding points of the thermosensitive chip and the pins with the PVC sheathed lines are wrapped with the second silica gel sealing layer in a sealing manner, and then are wrapped, sealed and solidified by epoxy encapsulating material; the third silica gel sealing layer extends to a protective sheath of the PVC sheathed lines, so as to wrap and seal a sensing head of the entire sensor. Epoxy potting compound is filled in the casing in a sealing manner, and the seal is realized through three layers of silica gel, so that the problem that the testing accuracy and service life are influenced as the temperature sensor is in a damp environment for a long time is solved; as the silica gel seal is adopted, the water-proof and damp-proof temperature sensor is anti-aging, resistant to high temperature, and excellent in water-proof, damp-proof and anti-aging effects, ensures the service life, and can be widely applied in the field of electronic products.