The invention discloses a garden rainwater collection and storage system and a construction method thereof. The system comprises a water penetration face, a water storage tank, a water collection ditch and a grit chamber. The grit chamber is arranged in the water collection ditch, a water passing pipe is arranged between the grit chamber and the water storage tank, the two ends of the water passing pipe are both provided with a filtering screen, and a sewage interception basket is arranged in the grit chamber. The water penetration face comprises a mineral filter layer, a substrate layer, an isolating layer, a water storage layer and a percolation layer, a water discharge pipe is arranged on the bottom of the percolation layer, and the water discharge pipe is communicated with the water storage tank. The construction method comprises the following steps that firstly, construction areas are divided; secondly, reconstruction is conducted along a river; thirdly, the water storage tank is constructed; fourthly, the water penetration face is constructed; fifthly, an original road is reconstructed; sixthly, a ground water suction device is installed in place. The system is high in water penetration capacity, infiltrated rainwater is purified and then collected and stored for standby application, the utilization rate of the rainwater is improved, the construction method is simple, orderly construction is achieved, local materials are used, resource waste is reduced, and the construction cost is low.