Sampling undisturbed lacustrine sediment is a critical job for environmental research. The recovery and undisturbedness of samples have direct effect on the environmental research results. Gravity corer is an efficient, cost-effective and easy-to-operate tool to sample shallow lacustrine sediment in lakes and reservoirs etc. water areas. Thus, it will improve the environmental research to study the sampling technology of gravity corer. This paper explains the specific sampling technology of gravity corer. On the basis of such research, it also presents a portable gravity corer, which is regarded as a suitable sediment sampling tool for environmental research sectors.