Based on the background of the concrete face crack repair project for the Garden Aqueduct in Anhui Province of China, mechanical tests were conducted to explore the effects of different amounts of styrene-acrylic mortar, water-cement ratio, curing humidity, and curing temperature on the mechanical properties and crack resistance of the concrete face. The test results show that increasing the styrene-acrylic mortar content and reducing the water-cement ratio can significantly improve the crack resistance of the styrene-acrylic mortar, manifested as an increase in flexural strength, a decrease in the compressive-flexural ratio, and an improvement in toughness and bonding strength. However, there was no significant improvement in compressive strength. It was confirmed that the styrene-acrylic mortar with 15% styrene-acrylic mortar content and a water-cement ratio of 30% exhibited optimal mechanical and crack resistance properties and is suitable for repairing cracks in the concrete face of the aqueduct. Additionally, higher curing humidity and temperature significantly improved the dry cracking resistance of the styrene-acrylic mortar. Under various curing conditions, the shrinkage rate of the styrene-acrylic mortar increased rapidly within the first 14 days and stabilized by day 28. Based on the test results, construction process optimization measures for the crack repair of the aqueduct concrete face were proposed, along with directions for future research.