The present invention discloses a novel overstandard sample retention instrument, which comprises an instrument body, wherein a water sample circulation pipeline is arranged on the right-rear side inside the instrument body and is connected to a water sample pre-treatment device, the water sample pre-treatment device is arranged on one side inside the instrument body, comprises a buffer cup, a filter, a homogenizing stirrer, a washing valve and a water discharge valve, and is connected to an overstandard sample retention device, the overstandard sample retention device comprises a peristaltic pump, a sampling bottle, a distribution arm and a water discharge funnel, the peristaltic pump is arranged on a peristaltic pump bracket positioned above the right side inside the instrument body, the sampling bottle, the distribution arm and the water discharge funnel are arranged inside a refrigeration box, the sampling bottle is arranged on a sampling bottle installation seat, the distribution arm is arranged above the sampling bottle, and the upper end of the instrument body is provided with a power supple and a control circuit board. The novel overstandard sample retention instrument of the present invention has characteristics of high integration degree, body miniaturization, and low cost.