Abstract: Fifteen compounds were successfully isolated from the total alkaloid content of Corydalis delicatula D. G. Long using a variety of chromatographic techniques, including silica gel, basic alumina, MCI, Sephadex LH-20 column chromatography, and HPLC. The structures of the isolated compounds were identified as (-)-tetrahydrocorysamine (1), corysamine (2), berberrubine (3), (-)-scoulerine (4), bicuculline (5), (-)-corlumine (6), scoulerine-β-N-oxide (7), salutaridine N-oxide (8), allocryptopine (9), protopine (10), coryximine (11), cryptopine (12), cis-N-methylstylopine (13), hunnemannine (14), and corlicatine A (15) through spectroscopic methods such as MS, NMR, and UV. These compounds were isolated for the first time from C. delicatula, and corlicatine A (15) is a new compound. Pharmacological testing revealed that compound 1 demonstrated excellent inhibition against Jack bean urease (JBU), with an IC₅₀ value of 1.28 µmol‧L^-1, surpassing the effectiveness of the positive control AHA. The synergistic inhibitory influence on JBU activity by compounds 1, 6, 11, 12 and inorganic reagents NaF and BA were proved by addition of competitive inhibitors NaF or BA. The molecular docking experiment between the most active alkaloid (-)-tetrahydrocorysamine (1) and the urease protein of the JBU was not found to interact with Ni²⁺, which is recognized as the active site of urease. Consequently, considering the impact of inorganic reagents on the inhibitory properties of alkaloids against JBU, it is hypothesized that the inhibitory effect of isoquinoline alkaloids on urease may involve targets or mechanisms other than Ni²⁺.