以腐植酸钾（KHA）和明胶（Ge）为天然高分子组分、丙烯酰胺（AM）和2-丙烯酰胺基-2-甲基丙磺酸（AMPS）为单体、过硫酸钾（KPS）为引发剂、N、N'-二亚甲基双丙烯酰胺（MBA）为交联剂，采用水溶液聚合法制备KHA/Ge/AM/AMPS水凝胶，利用FT-IR、SEM、TG对水凝胶的结构进行表征。通过压缩测试得到凝胶压缩强度为3.21 MPa，在压缩后未发生破裂并可迅速恢复原状；实验测得凝胶水接触角为61.5°，有良好的亲水性。同时，考察了水凝胶在人工胃液（pH=1.2）和人工肠液（pH=7.4）中对核黄素的释放性能。结果表明，水凝胶的溶胀与释药具有pH敏感性及优良的耐盐性能，水凝胶对核黄素的载药量为58.47 mg/g，包封率为49.56%。在pH=1.2的缓冲溶液中30 h药物累积缓释率为38%；在pH=7.4的缓冲体系中30 h的药物累积缓释率为67%，有良好的缓释效果，可用作胃肠道给药载体材料。

With potassium humic acid (KHA) and gelatin (Gel) as natural polymer compositions, acrylamide (AM) and 2-acrylamide-2-methyl propanesulfonic acid (AMPS) as monomers, potassium persulfate (KPS) as initiator, N, N'-dimethylene bisacrylamide (MBA) as crosslinking agent, KHA/Gel/AM/AMPS hydrogel is prepared via aqueous solution polymerization.FT-IR, SEM and TG are employed to characterize the structure of the prepared hydrogel.It is indicated through the compression test that the compressive strength of the hydrogel is 3.21 MPa, and the hydrogel does not crack in compression and can quickly return to its original state.The water contact angle of the hydrogel is 61.5°, showing a good hydrophilicity.The release properties of the hydrogel to riboflavin in artificial gastric juice (pH=1.2) and artificial intestinal fluid (pH=7.4) are investigated.It is found that the swelling and drug release performances of the hydrogel have sensitivity to pH and excellent resistance to salt.The hydrogel can load 58.47 mg·g^-1 of riboflavin, with an encapsulation rate of 49.56%.The cumulative sustained-release rate of the hydrogel to drugs has reached 38% in the buffer solution with a pH of 1.2 in 30 hours, and 67% in the buffer solution with a pH of 7.4 in 30 hours.It is proved that the hydrogel has a good sustained-release effect and can be used as a carrier material for gastrointestinal administration.