The utility model provides a gear box gear oil level warning device, belongs to gear box technical field. The inside wall of gear box is improved level and is equipped with gear oil level line, and the gear box top is equipped with the through -hole, and the demountable installation of through -hole department has the gear box lamina tecti, has offered the mounting hole on the gear box lamina tecti, and the static pressure level gauge passes the mounting hole of gear box lamina tecti and bottom in the gear box is placed to the through -hole at gear box top, and the sensor of static pressure level gauge passes through the external warning bulb of wire series, bee calling organ and power, when the pressure value of static pressure level gauge was less than the standard value, the gear oil level was on the low side in the suggestion gear box that sensor external circuit switches on that the alarm lamp bubble point is bright, the buzzing of bee calling organ is reported to the police, needbe to adding gear oil in the gear box, when the pressure value of static pressure level gauge equaled or is higher than the standard value, the warning bulb went out, bee calling organ stops the buzzing. The utility model discloses the bearing that can prevent the gear box is damaged because of lacking oil, the utility model discloses but the wide application is in various types of gear boxes, reduction gear.