The deep-sea large-scale biological trapping observer is a set of fully automatic deep-sea in-situ ecological observation and biological sampling lander, which has the characteristics of low power consumption, high safety and low maintenance. The equipment can be placed on a scientific survey ship or other ship with a crane, dive to the seabed under the influence of gravity to conduct submarine ecological observations, trap biological samples, and conduct other in-situ scientific experiments such as microbial culture. The weights can be released regularly or through deck acoustic commands, relying on buoyancy to float to the surface for recovery.