Three types of self‐prepared chemical dust suppressants (CDSs) were investigated for their inhibitory effects on nitrocellulose (NC) cloud dust explosion. The results revealed that NC is extremely sensitive to electric sparks and has a high explosion intensity. CaCl2‐CDS effectively increased the particle size to control fly dust substantially inhibiting dust cloud explosions. However, both Na2SO4‐CDS and MgCl2‐CDS exhibited poor abilities and even promoted explosion. Therefore, neither Na2SO4‐CDS nor MgCl2‐CDS is recommended as a CDS for NC. Inappropriately using CDSs may engender severe explosions. Furthermore, a mechanism underlying NC dust cloud combustion and explosion was proposed. NC has three stages of heat release: autoxidation, thermal decomposition, and combustion. Thermal decomposition, combustion, and explosion were triggered depending on the energy provided from autoxidation. CaCl2‐CDS inhibited only combustion. This study reveals the mechanism underlying NC dust cloud explosions and provides useful information for the development of more optimized CDSs.