The invention provides an oil quantity detection device for an oil disc of a sewing machine. The oil quantity detection device comprises the oil disc provided with an oil cavity, and further comprises a support which is fixedly arranged in the oil cavity, a floater which is located in the oil cavity and can float up and down along the height change of an oil level in the oil cavity, and an element to be induced, which is fixedly arranged on the floater, wherein the support is internally provided with a sealing cavity; and the sealing cavity is internally and fixedly provided with sensors for inducing the element to be induced. According to the oil quantity detection device, the sensors are arranged at the positions with different heights in the oil cavity of the oil disc, so that when the floater drives the element to be induced to float up and down along the height change of the oil level of lubricating oil in the oil cavity, the sensors can induce the element to be induced, and furthermore, high-level oil quantity information or low-level oil quantity information in the oil disc is detected; and a maximum value and a minimum value of the oil quantity in the oil disc can be measured at the same time, so that a phenomenon that the oil quantity in the oil disc is excessive or too less is prevented, the normal work of the sewing machine can be guaranteed, and oil is prevented from leaking when the sewing machine turns on one side.