The invention discloses the application of the maleimide compound represented by formula I as a chitin synthase inhibitor, wherein R 0 is phenyl, benzyl, phenethyl, phenylpropyl, p-fluorophenyl, p-chlorophenyl, p-bromophenyl, p-methoxyphenyl, p-methylphenyl or p-hydroxyphenyl; R 1 is hydrogen, methyl, phenyl or chlorine; R 2 is hydrogen, methyl, phenyl or chlorine. The maleimide compound provided by the invention has a good inhibitory effect on chitin synthase.