For a direct-injection spark-ignition (DISI) methanol engine retrofitted from a four-cylinder diesel engine, fuel is injected into the cylinder during the intake stroke to realize the homogeneous charge combustion for the high power output. The cylinder pressure of typical operating conditions was measured and analyzed. The effects of different parameters on methanol engine combustion characteristics were investigated. The results showed that the maximum power output and torque of the methanol engine are 5.88% and 20.90% higher than original diesel engine, respectively. The maximum brake thermal efficiency reaches 35.3% at a speed of 1500r/min, and a brake mean effective pressure of 0.85MPa, which is higher than the conventional gasoline engine. The ignition delay period and rapid combustion phase increase with decreasing load. The start of combustion is postponed with increasing speed at full load. The ignition delay period and rapid combustion phase increase with increasing speed under full load. The change of the cyclic variations has the approximate trend with that of the ignition delay period at different operating conditions.