Abstract: To elucidate the critical ignition mechanisms and governing principles of ammonia-coal co-firing under industrially relevant turbulent swirling conditions, and to address the ignition stability challenges in coal-fired boilers, a systematic investigation of pulverized coal flame ignition characteristics is conducted on a custom-built tubular dual-swirl burner platform. Optical diagnostics and image processing techniques are utilized to quantitatively analyze the effects of the ammonia injection strategy （premixed with primary air vs. staged with secondary air）, ammonia energy share （E_\mathrmNH_3 , 0−50%）, and global equivalence ratio （Φ_total, 0.59−0.95） on the ignition delay time. It is revealed that the ammonia injection strategy is identified as the dominant factor controlling coal ignition performance. Compared to the premixed mode, coal ignition is significantly enhanced by staged injection （ammonia supplied with secondary air）. At a constant ammonia share （E_\mathrmNH_3 = 30%）, the ignition delay time of the downstream coal flame is observed to decrease remarkably from 9.8 ms （premixed） to 4.4 ms, representing a reduction exceeding 55%. This phenomenon is attributed to the formation of an independent high-temperature ammonia flame within the secondary air stream, which provides a high-enthalpy environment for pulverized coal particles in the primary air. Consequently, the competitive consumption of oxygen between the two fuels within the oxygen-lean primary air is effectively mitigated, thereby achieving rapid ignition. Under the staged mode, the ignition delay is effectively reduced by increasing the ammonia share, with a monotonic shortening trend observed in the upstream coal ignition delay as E_\mathrmNH_3 increases from 10% to 50%. Conversely, coal ignition is inhibited by a decrease in the global equivalence ratio; specifically, as Φ_total decreases from 0.95 to 0.59 （at E_\mathrmNH_3 = 50%）, the downstream ignition delay time is prolonged from 6.1 ms to 8.3 ms. In the premixed mode, a distinct spatial dependence of the ammonia share impact is exhibited: Ignition in the upstream near-field region is delayed with increasing E_\mathrmNH_3 , whereas it is accelerated in the downstream region. It is concluded that implementing spatially staged injection of ammonia and coal is established as a fundamental approach to ensuring stable ignition in high-share ammonia-coal co-firing systems. The control strategies and mechanisms revealed herein provide a crucial scientific basis for the design and optimization of industrial-grade ammonia-coal co-firing burners.