The invention provides a method for recycling and preparing beta-silicon nitride from the surface of a waste quartz crucible. The method comprises the following steps: 1, adding diluted acid to silicon nitride raw materials containing impurities such as silicon dioxide, silicon and metal, conducting the first normal-temperature acid pickling, and removing the metal impurities; 2, conducting the secondary hydrofluoric acid pickling, and removing silicon dioxide and part of silicon; 3, adopting pure water for cleaning the mixture till the mixture becomes neutral, and conducting vacuum drying; 4, conducting high-temperature nitrogen treatment at the temperature of 1300-1550 DEG C, and obtaining the beta-silicon nitride; 5, conducting ball-milling, pulverization, screening and grading, and selecting the beta-silicon nitride with the granularity smaller than 10 micrometers. By means of the method, high purity recycling and reuse of a silicon nitride coating on the surface of the waste quartz crucible are achieved, and the obtained beta-silicon nitride can serve as a toughened material in production of silicon nitride ceramics.