The invention relates to an effervescent tablet containing propiconazole and a preparation method thereof. The effervescent tablet is prepared from propiconazole, a nano-carrier, an acid source, a carbon dioxide source, a bonding agent, a wet dispersing agent, a disintegrating agent and a lubricating agent. The preparation method comprises the following steps: firstly, solidifying the propiconazole, and then, directly tabletting by adopting dry powder to obtain the effervescent tablet containing propiconazole. The tablet has small volume and can be transported and stored very conveniently. When in use, the tablet can quickly disintegrate in water to become a pesticide suspension which can be sprayed in paddy fields and can be widely used for preventing and treating crop diseases.