The PCBER gene belongs to the PIP subfamily and is an important gene involved in the synthesis of lignans in the phenylpropane metabolic pathway. In this study, The GhPCBER plant overexpression vector pGWB17GhPCBRE was constructed and transformed into Arabidopsis thaliana, and gene silencing recombinant vector pTRV2GhPCBER was also constructed and transformed into cotton. Real time quantitative PCR was used to analyze the expression of GhPCBER gene under different tissues.The lignin and lignan contents in stem and leaf tissues from transgenic A. thaliana and cotton plants were extracted and determined. The results showed that: (1) GhPCBER plant overexpression vector pGWB17GhPCBRE and gene silencing recombinant vectors pTRV2GhPCBER were successfully constructed. Six transgenic A. thaliana lines with overexpression GhPCBER were obtained by genetic transformation, and GhPCBER gene silenced cotton plants were obtained(5 strains as a group). (2) PCR analysis showed that six transgenic Arabidopsis thaliana lines were overexpressing lines, among which the relative expression of lines 1, 2 and 3 was higher, and the expression in stem and leaf tissues was 7-14 and 6-16 times higher than that of wild type, indicating that the GhPCBER gene was successfully overexpressed in A. thaliana; The expression levels of GhPCBER gene silencing cotton plants in stems and leaves were 12% and 26% lower than those in wildtype cotton plants, respectively, indicating that the tobacco fragile virus (TRV) system (pTRV2GhPCBER) successfully inhibited the expression of GhPCBER gene. (3) The contents of lignin and lignan in stems and leaves of GhPCBER transgenic A. thaliana were significantly lower than that of wild type; the contents of lignin and lignan in stems and leaves of GhPCBER gene silencing cotton plants were significantly lower than that of wild type; Histochemical staining observation showed that the color of the stem of GhPCBER gene silencing cotton plants was significantly lighter than that of wild type, which also proved that the lignin content in the stems of silenced cotton plants decreased; (4) Realtime quantitative PCR analysis of eight related genes in the phenylpropanoid metabolic pathway revealed that overexpression or inhibition of the GhPCBRE gene resulted the reorientation of the phenylpropanoid metabolic pathway.