To improve the resistance of the rice variety Jiabare from Motuo, to rice blast and bacterial leaf blight, molecular marker-assisted selection (MAS) technology was employed. Through hybridization, backcrossing, selfing, and integration with MAS technology, the rice blast resistance genes Pik-H4, Pita, Pi2, and the bacterial leaf blight resistance gene Xa23 carried by the donor parent H437 were introduced into Jiabare, three improved lines, designated as L1, L2, and L3, were successfully obtained. Disease resistance evaluation results indicated that the resistance of these three improved lines to both rice blast and bacterial leaf blight was significantly enhanced, with their resistance levels markedly superior to that of the highly susceptible variety Jiabare. In terms of agronomic traits, except for the significantly lower plant height of L2 (162.3 cm) compared to Jiabare (166.7 cm), the other agronomic traits of the improved lines showed no significant differences from those of Jiabare. Regarding quality traits, indicators such as brown rice rate, head rice rate, and amylose content of the improved lines were basically consistent with those of Jiabare. This study demonstrates that the aggregation of multiple broad-spectrum resistance genes using MAS technology can directionally enhance the resistance of Jiabare to rice blast and bacterial leaf blight. This research outcome provides practical and effective strategies for the disease-resistant improvement and industrial application of rice varieties in Xizang regions.