Ecological ditch system for collecting initial rainwater without affecting flood draining

The invention discloses an ecological ditch system for collecting initial rainwater without affecting flood draining. The middle part of a ditch main body consists of a treatment ditch and a flow dividing ditch which are arranged in parallel, wherein the treatment ditch is formed by encircling of a wetland dam; the flow dividing ditch is separated by a flow dividing dam; the wetland dam is combined with the flow dividing dam to transversely cut a ditch main body; the wetland dam rises above the flow dividing dam; a water inlet is formed in the bottom part of the wetland dam body positioned at the upstream; a water outlet is formed in a consistent horizontal height part of the wetland dam positioned at the downstream and the water inlet; a water retaining splitter plate is arranged behind the water inlet; a winding corridor type constructed wetland is arranged in the treatment ditch; when the flow rate of the rainwater which flows through the ditch main body is more than the maximum flow rate of the water inlet, a majority of rainwater crosses over the flow dividing dam and drains into the downstream of the ditch through the flow dividing ditch. The ecological ditch system has the advantages that the initial rainwater can be effectively purified and the flood can be drained in time when the high-flow rainwater flows through the ditch.