The utility model relates to an in-situ measuring device for sea-bottom depositional optical parameters, comprising a gravity sampler, transmission energy converters, receiving energy converters and a central control device containing control program, wherein a gravity sampling pipe is arranged below the gravity sampler, and the central control device is arranged above the gravity sampling pipe of the gravity sampler; and the at least four transmission energy converters and the at least four receiving energy converters are fixed on the gravity sampling pipe through a support bracket, wherein the two transmission energy converters are symmetrically arranged on the external surface at the upper part of the gravity sampling pipe, the other two transmission energy converters are symmetrically arranged on the external surface at the lower part of the gravity sampling pipe, the receiving energy converters are all arranged on the gravity sampling pipe between the two transmission energy converters, and the axes of the transmission energy converters and the receiving energy converters are all parallel to the axis of the gravity sampling pipe. The in-situ measuring device has simple structure and obvious detection effect, thereby increasing the detection depth and improving the adaptability to different geological conditions, obviously improving the propagation distance of the energy converters, and greatly saving the detection cost and time.