The invention discloses a novel waste oil device which comprises a placement plate fixedly arranged on a wall face, a backward flowing tank fixedly installed on the right end face of the placement plate and a guiding cylinder fixedly installed on the ground. An empty groove with an upward groove opening is formed in the guiding cylinder, a backward flowing port with an upward groove opening is formed in the backward flowing tank, a partition net is fixedly arranged in the backward flowing port, an empty pipe is fixedly installed at the bottom of the backward flowing tank, the lower end of theempty pipe penetrates into the empty groove, a left slippage cavity and a right slippage cavity are formed in the front end wall and the rear end wall of the empty groove in a bilateral symmetry mode,the left slippage cavity and the right slippage cavity are provided with a left slippage block and a right slippage block respectively in a vertically slippable mode, a left connecting arm and a right connecting arm are fixedly arranged on the inner side end face of the left slippage block and the inner side end face of the right slippage block respectively, a left protruding shaft and a right protruding shaft are arranged on the left connecting arm and the right connecting arm respectively, and a warped plate is rotatably installed between the left connecting arm and the right connecting armthrough a rotary hinge pin.