Engine lubricating oil quantity measurer and engine and automobile thereof

The invention discloses an engine lubricating oil quantity measurer and an engine and an automobile thereof, wherein the measurer comprises a guide tube, a floater, a measuring rod, a photoelectric sensing head and an alarm module; the floater can be in contact with the level of lubricating oil; the measuring rod is movably arranged in the guide tube, is connected with the floater and is coated with photosensitive material; the photoelectric sensing head is arranged on the sidewall of the guide tube, and is arranged at a position which corresponds to the position of the photosensitive material at the lower limit or the upper limit of the level of lubricating oil; and the alarm module, which is connected with the photoelectric sensing head through a wire, is used for giving the alarm according to the signal transmitted by the photoelectric sensing head. The invention can automatically give the alarm when the quantity of lubricating oil reaches the lower limit, overcomes the defect of the prior art that the eff