Traumatic brain injury (TBI) usually results from brain shaking or impact. It can affect the normal function of the brain and even cause people become disabled and death. However, there is lack of studies for the physiological changes of humans or animals under brain injury. In order to obtain the information of physiological state change, we designed and enforced a non-invasive, wireless multi-channel near-infrared spectroscopy (NIRS) for monitoring the concentration change of oxy-hemoglobin (HbO2), deoxy-hemoglobin (HbR) and total-hemoglobin (HbT) continuously during and after TBI. The experimental results indicated that the concentration change of HbO2 and HbT is significantly related to the impact strength and infarction volume. Thus, this system is easily used and stable for TBI study.