Mother liquid treatment method during production of pentaerythritol

The invention relates to a mother liquid treatment method during production of pentaerythritol, which includes the following steps: 1) feeding a centrifugal mother liquid in production of pentaerythritol into six settlement tanks: V1, V2, V3, V4, V5 and V6, for performing stepwise settlement, temperature in the V1 and V2 being 65-70 DEG C, and temperature in the V3, V4, V5, V6 respectively being 45-50 DEG C, 35-40 DEG C, 25-30 DEG C and 18-23 DEG C; and 2) after settlement in the last one stage of the settlement tank, filtering the mother liquid through a plate-and-frame filter press. The method improves efficiency of settlement, wherein the mother liquid is firstly heated and then is cooled, so that the pentaerythritol can be crystallized as most as possible. After filtration, the content of the pentaerythritol in clear liquid is greatly reduced while content of sodium formate is significantly increased, thereby achieving excellent product quality. The content of the pentaerythritol in clear liquid is reduce