An upgrade to the STAR detector system at forward rapidities has been completed before the RHIC RUN 2022. It consists of the Forward Tracking System (FTS) and the Forward Calorimeter System (FCS). The Forward Tracking System is composed of a Silicon Tracker and a small-strip Thin Gap Chamber Tracker. The Forward Calorimeter System contains an Electromagnetic Calorimeter and a Hadronic Calorimeter. These systems cover the pseudorapidity region of 2.5 < η < 4, providing detection capabilities for neutral pions, photons, electrons, jets, and charged hadrons. This enables the STAR experiment to study cold QCD physics at very high and low regions of Bjorken x and to explore the longitudinal structure of the initial state in relativistic heavyion collisions by measuring the decorrelations at large η. This proceeding will introduce the STAR forward upgrade, its current status, and its performance during the STAR Run22.