In the past 30 years, to solve three problems involved in quality and safety of tea, namely how to set the scientific maximum residue limits (MRLs) in tea, how to control the pesticide and contaminant residue, and how to improve detection method, the principal of “effective risk assessment” by using tea infusion was innovated. Based on that, the principal of global MRLs on tea was reconstructed. The key point in the control of pesticide residues and important contaminants was revealed, and the selection principal and application technology of pesticides were established. The in-situ and high-throughput analytical methods for pesticides and contaminants in tea were developed. The control system based on “MRLs fixation, residue control and recognition detection” was constructed and popularized. These work would promote the scientific and technological progress of the sustainable development of tea industry in China.