The invention discloses a self-recovery MBUS host bus protection circuit, which comprises an over-current protection circuit. The over-current protection circuit comprises a current detection unit anda self-recovery protection unit which are connected in series. The current detection unit comprises an instrument differential amplification circuit, an over-current threshold circuit and a first comparator U2A which are connected in series. The self-recovery protection unit comprises a self-recovery delay circuit and an MBUS bus fast cut-off circuit which are connected in parallel. The self-recovery delay circuit comprises a delay threshold circuit, a charging circuit, a second comparator U4A and a first triode Q2. The self-recovery MBUS host bus protection circuit realizes a self-recovery over-current protection function and a safety protection function. The current detection unit adopts an instrument differential amplification circuit, which has the characteristics of differential input impedance balance, low output impedance, and isolation from the signal input end through an internal feedback resistor network in closed-loop gain. Therefore, the suppression ratio of common-mode signals is greatly improved, and the stability of current detection and the anti-interference ability are ensured.