Developing a sensor with high selectivity and fast response-recovery time for detecting ammonia gas in complex environments is a challenging task. However, recent polymer-based ammonia gas sensors often suffer from low sensitivity and long response-recovery time. In this work, with the assistance of sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfate(SDS), and lauryl amine (LA), the PANI films were prepared by interfacial synthesis to obtain the ordered polymer chains and applied to NH3 sensors. At room temperature, the SDS-functionalized PANI film-based sensor shows a good response to NH3 (5.4 for 40 ppm NH3), the detection limit is 0.1 ppm, and the recovery time is 12 s, which is better than that similar base on PANI. The functionalized PANI film has an ordered structure to accelerate the electron transport rate and the protonation/deprotonation properties, which make the sensor have excellent gas sensing performance. In addition, the sensor has good reproducibility, moisture resistance, and long-term stability. This result provides important opinions for realizing polymer materials with high gas-sensing properties to NH3.