The invention discloses a shock wave attenuation structure of a protective door of a railway tunnel. The protective door comprises a door leaf. At least one groove is formed in the bottom of the door leaf along the thickness direction of the door leaf and continuously or intermittently extends along the width direction of the door leaf. Porous material filling layers are fixedly arranged on the inner walls of the grooves. The shock wave attenuation structure has the advantages that shock wave pressures which are transmitted to the back of the door leaf from lower door slots can be effectively reduced, and accordingly the safety of personnel behind the door leaf can be guaranteed.