Tight gas wells commonly adopt downhole throttling for production, making direct measurement of bottom-hole static and flowing pressures challenging, costly, and disruptive to continuous production. The conventional method involves converting wellhead casing pressure to estimate bottom-hole pressure, but this approach lacks rigorous constraints, resulting in significant calculation errors. In this study, we establish a comprehensive wellbore pressure correlation model by considering throttling-induced pressure drops. The model integrates pressure balance relationships between: Bottom-hole pressure and casing pressure drop, Bottom-hole pressure and pre-throttling pressure drop, Throttling pressure drop, and Post-throttling pressure drop. Using the proposed model, the bottom-hole pressure is further used to calculate wellhead tubing pressure along the tubing from bottom-hole to the wellhead. The accuracy of bottom-hole pressure estimation is then evaluated by comparing the calculated tubing pressure with actual measurements. Since the same wellbore pressure drop model is applied for both casing-pressure-to-bottom-hole-pressure conversion and bottom-hole-pressure-to-tubing-pressure calculation, the calculated tubing pressure should match the measured value if the theoretical model aligns with the actual wellbore flow regime—provided throttling effects are properly accounted for. If discrepancies exist, errors propagate from the bottom-hole pressure estimation to the tubing pressure calculation, allowing iterative parameter adjustments to minimize tubing pressure errors and thereby improve bottom-hole pressure accuracy. Application results in the Sulige Gas Field demonstrate that the proposed method reduces: Average static pressure error by 19.6%, and Average flowing pressure error by 18.8%. This approach provides a reliable foundation for evaluating production performance in downhole-throttled gas wells.