Abandoned, lost or otherwise discarded fishing gear (ALDFG) is one of the most serious hazards of marine ecology and fisheries. The problems triggered by ALDFG have attracted increasing attention from many countries and international organizations around the world. This paper reviews the harm of ALDFG to marine ecology and fisheries, the primary causes of ALDFG, the steps proposed by states and relevant international organizations to remove ALDFG, and the commonly used ALDFG survey and evaluation methods in recent years. It has been found that in recent years, most of the studies on ALDFG used statistical models to quantify ALDFG, or combined with statistical tests to assess the harmfulness of ALDFG (ghost fishing) and to evaluate the ecological and economic benefits of clearing ALDFG, etc. This paper suggests that: (1) the questionnaire survey and underwater field survey should be used to assess the amount and harm of ALDFG in the national jurisdictional area, and analyze the trajectory of ALDFG by ocean dynamics models combining with the hydrodynamics of fishing gear; (2) the new materials should be developed and the design of fishing gear and ancillary gear should be improved to reduce the ALDFG；(3) the physical change in the process and the change of ghost fishing capacity of underwater ALDFG should be studied by field survey；(4) the positive role to the marine ecological system diversity and fishery resources should be studied after the underwater ALDFG removed, and the social and economic benefit should be evaluated by the economic model analysis after the underwater ALDFG removed.