Objective To observe the effect of ossotide injection on bone mineral density (BMD), bone microstructure and biomechanical properties and mRNA expression of small intestinal calcium binding protein (CaBp?D9K), and to study the mechanism of ossotide injection in the treatment of ovariectomized osteoporosis. Methods Forty?eight 3?month old SPF male rats with successful modeling (excision of bilateral ovaries) were randomly divided into theobservation group and model group, 24 normal rats were divided into sham operation group (excised part of the mesenteric membrane), and 24 normal blank group. The blank group, sham operation group and model group were given normal saline, and the observation group was intragastrically given 1.1 mg/ kg ossotide. Two months after intervention, the bone volume (BV), trabecular bone volume (Tb. Th), trabecular number (Tb. N), trabecular separation (Tb. Sp), bone mineral density, bone biomechanics, serum 1,25 (OH)2 D3 levels and CaBp?D9K mRNA expression levels of small intestine were assessed and statistically analyzed. Results The bone mineral density, maximum load, fracture load, BV, Tb. Th, Tb. N, serum 1,25 (OH) 2D3 and intestinal CaBp?D9K mRNA expression level in the model group were significantly lower than those of the control group and sham operation group ( P < 0.05), Tb. Sp of the model group was significantly higher than that of the control group and sham operation group ( P < 0.05). The bone mineral density, maximum load, fracture load, BV, Tb. Th, Tb. N, serum 1,25(OH)2D3 and intestinal CaBp?D9K mRNA expression level in the observation group were significantly higher than those of the model operation group, and the Tb. Sp of the observation group was lower than that of the model group ( P < 0.05). Conclusions Ossotide injection treatment can reduce the degree of osteoporosis in ovariectomized rats, increasing intestinal CaBp?D9k mRNA expression and promoting intestinal calcium absorption may be its important mechanisms of action.