The invention relates to a mosquito-killing Bacillus thuringiensis suspended slow release formulation and a preparation method thereof. According to the preparation method of the present invention, using sodium alginate as a carrier and calcium chloride as a crosslinking agent, a mosquito-killing Bacillus thuringiensis raw powder is added as an effective active ingredient, and the slow release formulation has a high-efficiency mosquito-killing activity； the formulation has a suspended slow release effect via hollow glass beads, thus resisting ultraviolet radiation and prolonging the longevity of residues. The formulation has a reasonable formula, high insecticidal toxicity, good control effect, strong ultraviolet radiation resistance and long longevity of residues in the wild. The experiment indicates that the product of the invention has a good effect on killing mosquito larvae in water, and as the treatment time is prolonged, the average relative death rate of test insects is gradually increased until the relative death rate of test insects within 192 hours reaches 100%； and the product of the invention has a high mechanical property and long-acting suspension property, and the suspension begins to precipitate at 144 hours, and the suspension rate is kept to be 58.3% for 192 hours.L'invention concerne une formulation retard suspendue de Bacillus thuringiensis pour l'élimination des moustiques, et un procédé de préparation de celle-ci. Le procédé de préparation de la présente invention, qui utilise de d'alginate de sodium en tant que vecteur et du chlorure de calcium en tant qu'agent de réticulation, consiste à ajouter une poudre brute de Bacillus thuringiensis pour l'élimination des moustiques en tant que principe actif efficace, cette formulation retard possédant une activité très efficace d'élimination des moustiques ； la formulation présente un effet retard suspendu grâce à des billes de verre creuses, ce qui lui confère une résistance au rayonnement ultraviole
