Comprehensive sampling device for marine geological survey

The invention discloses a comprehensive sampling device for marine geological survey, the comprehensive sampling device comprises a comprehensive sampling body and a seabed material sampling assembly, a seawater sampling assembly and a gas collecting assembly which are installed on the comprehensive sampling body, the comprehensive sampling body is a circular truncated cone-shaped frame, the upper table top of the circular truncated cone-shaped frame is a mounting disc, the mounting disc is divided into two layers, the two mounting discs are respectively an upper mounting disc and a lower mounting disc, the area of the lower mounting disc is equal to that of the upper mounting disc, and the upper mounting disc and the lower mounting disc are fixed through a vertical fixing rod. When the device is put into a preset site for collecting samples in the sea, the device can be used for collecting gas released from seawater, seawater and bottom mud and seabed soil samples at the same collection site, so that the col