Celecoxib is a sulfanilamide nonsteroidal anti-inflammatory drug that can selectively inhibit cyclooxygenase-2 to inhibit prostaglandin production, achieving anti-inflammatory and analgesic effects. This study investigated the pharmacokinetics, safety, and bioequivalence of a single oral dose of celecoxib capsule (the test or reference preparation) in healthy volunteers under fasting and fed conditions. A single-center, randomized, open, single-dose, double-cycle crossover self-control design was conducted: 40 healthy volunteers were enrolled in the fasting and fed groups, respectively. A completely randomized method was used, with one group taking the test celecoxib preparation (T) and the other taking the reference celecoxib preparation (R). During the administration period, the safety of the drug was evaluated simultaneously, and venous blood was collected at the corresponding time points. The concentration of celecoxib in plasma was measured by liquid chromatography-tandem mass spectrometry. The main pharmacokinetic parameters were logarithmically converted and analyzed for variance. The 90% confidence interval for the bioavailability of the T compared to the R was calculated using maximum drug plasma concentration, area under the plasma concentration-time curve from time zero to the last quantifiable concentration point, and area under the plasma concentration-time curve from time zero to infinity for a single oral dose in volunteers, and the data obtained were all between 80% and 125%, indicating that the T and R have bioequivalence and good safety during fasting and fed administration.