Tea belongs to alkaline plants, and general pesticides are basically acidic. According to the dosage and times of use, the processing method is tested and calculated, and the residue period is roughly three months to six months. Water washing can only wash away the water-soluble pesticides on the surface. For the water-insoluble pesticides, the systemic pesticides with high decomposition temperature will be adsorbed in the gaps such as cellulose and are not easy to wash off.