Method for purifying sucralose

A method for purifying sucralose, comprising:

• removing a solvent from a sucralose reaction solution to obtain a concentrated crude sucralose solution;
• under stirring, adding ethyl acetate into the concentrated crude sucralose solution, heating to a preset temperature, and holding at the preset temperature for a first preset time to obtain a crude product slurry containing sucralose crystal;
• and
• under stirring, subjecting the crude product slurry to gradient cooling to an endpoint temperature, holding at the endpoint temperature for a second preset time, and filtering to obtain the sucralose crystal;
• wherein
• the preset temperature is in a range of 45° C. to 65° C.,
• the first preset time is in a range of 0.5 h to 3 h,
• the gradient cooling is conducted as follows:
• cooling the crude product slurry to the endpoint temperature at a cooling rate of 1° C./10 min to 3° C./10 min, and the endpoint temperature is in a range of 0° C. to 10° C., and
• the second preset time is in a range of 0.5 h to 3 h.