An integrated physiological signal acquisition system comprises an analysis host, a physiological signal acquisition element and at least one biological sensor coupled to the physiological signal acquisition element for sensing a physiological signal of a user. The physiological signal is transmitted to the physiological signal acquisition element. The physiological signal acquisition element transmits the physiological signal to the analysis host for analysis. The at least one biological sensor is a pluggable biological sensor. Accordingly, only an analysis host and a physiological signal acquisition element are need to you realize different physiological signal detection, thus, the cost of hardware can be significantly reduced.