The invention relates to a vascular targeting embolism sustained release agent of a triple compound microsphere for an antituberculosis drug, a preparation method and applications thereof. The sustained release agent comprises a carrier and a drug, wherein the drug is encapsulated by the carrier, the carrier is selected from sodium alginate or chitosan, and the drug is a triple compound antituberculosis drug which comprises rifampin, isoniazide and pyrazinamide or moxifloxacin. Three antituberculosis drugs are employed as matrixes of a drug solution, sodium alginate or chitosan is used as a carrier solution, and a prepared solution is obtained by mixing the drug solution and the carrier solution. A polymer solution having the drug is enabled to be dispersed into droplets with certain particle sizes and to be sprayed into a curing liquid through a method of high voltage electrostatic droplets, and thus the microsphere for the antituberculosis drug are prepared in the presence of calcium ions. The embolism sustained release agent can be used in the drug for treating pulmonary tuberculosis, pulmonary tuberculosis massive hemoptysis, cavitary pulmonary tuberculosis, renal tuberculosis, osteoarticular tuberculosis, genital tubercolosis, thyroid tuberculosis, tuberculosis of cervical lymph nodes, pericardial tuberculosis, chest-wall tuberculosis and other in-vivo tuberculosises.