Since 2009, the coal-to-ethylene glycol technology via syngas has been rapidly expanded in China, and the total production capacity of ethylene glycol is estimated to reach 13.68 Mt/a by 2022. The increasing maturity of coal-to-ethylene glycol technology further drives the technical progress of biodegradable plastic polyglycolic acid from coal via syngas, that is, dimethyl oxalate in the coal-to-ethylene glycol technology is selectively hydrogenated to methyl glycolate, and then the methyl glycolate is polymerized to degradable plastic polyglycolic acid. Polyglycolic acid is not only positioned as a high-end product in the polyester industry, but also used to produce fully degradable polyester products. It is a new material that has great market demand potential and space, encouraged by countries and regions where the "plastic limit order" is implemented. Thus, the R & D of the branch technology of degradable polyglycolic acid from coal via syngas is of great significance to enrich the product structure of the coal-to-ethylene glycol industry. Focusing on the R & D progress of degradable polyglycolic acid from coal via syngas, this review discussed the technical principle of hydrogenation of dimethyl oxalate to methyl glycolate monomer and polymerization of methyl glycolate to polyglycolic acid, as well as the engineering design and feasibility of this technical route. For the synthesis of methyl glycolate monomer, the key technology to achieve high conversion of dimethyl oxalate and high selectivity of methyl glycolate lies in designing and adjusting the composition and structure of the catalyst and optimizing the reaction conditions. For the preparation of polyglycolic acid from methyl glycolate, there are two main techniques: direct polycondensation method with methyl glycolate or glycolic acid as raw material and ring-opening polymerization method with glycolide as raw material. The quality of polyglycolic acid products can be significantly affected by different polymerization processes: low molecular weight polyglycolic acid can be produced by direct polycondensation and high molecular weight polyglycolic acid can be produced by ring opening polymerization. The development of degradable polyglycolic acid technology from coal via syngas will be conducive to the development and expansion of China′s coal-to-ethylene glycol technology.