Wearable sweat sensors with various sensing systems can provide noninvasive medical diagnostics and healthcare monitoring. Here, we demonstrate a wearable microfluidic nanoplasmonic sensor capable of refreshable and portable recognition fingerprint information of targeted biomarkers including urea, lactate, and pH in sweat. A miniature, thin plasmonic metasurface with homogeneous mushroom-shaped hot spots and high surface-enhanced Raman scattering (SERS) activity is designed and integrated into a microfluidics platform. Compared to conventional wearable SERS platforms with the risk of mixed effect between new and old sweat, the microfluidic SERS system allows sweat administration in a controllable and high temporal-resolution fashion, providing refreshable SERS analysis. We use a portable and customized Raman analyzer with a friendly human-machine interface for portable recognition of the spectroscopic signatures of sweat biomarkers. This study integrates epidermal microfluidics with portable SERS molecular recognition, presenting a controllable, handy, and dynamical biofluid sensing system for personalized medicine.