An eco-friendly and low-cost hydrogel of BT-g-CMC were prepared vis chemical cross-linking, its structure and morphology were characterized, and it was used for phosphorus recovery from wastewater and slow-release phosphorus fertilizer. The adsorption studies indicated that the hydrogel showed good affinity for H2PO4- with an adsorption capacity of 18.78 mg/g at 298K when the quality ratio of CMC/BT was 1:1. The adsorption system could reach equilibrium within 120 min. Afterward, the phosphate-rich BT-g-CMC1.0 hydrogel was used as slow-release fertilizer (SRFs). The results showed that the product with excellent water-retention and slow-release capacities. The pot experiments showed that the SRFs played a positive role in vegetable growth. The soil remediation experiment displayed that 82.9% of Cr (Ⅲ) in the soil could be inhibited when SRF dosage was 0.3g for three times leaching. Therefore, SRFs has broad industrial and green agricultural applications.