The present invention discloses a method for preparation of porous carbon electrode materials by employing a plant root system. A plant root system performs surface cleaning, is subjected to vacuum freeze drying and then pre-carbonation in a temperature of 400-600 DEG C for 1-4 hours, is soaked in diluted hydrochloric acid for 40-48 hours, is subjected to suction filtration, ultrapure water cleaning and drying, and finally performs total carbonization treatment in a temperature of 600-900 DEG C for 1-4 hours, and porous carbon materials with a well-ordered porous structure and a high specificsurface area are obtained. An electrochemical performance test shows that the prepared porous carbon materials are taken as supercapacitor electrode materials, are low in impedance, high in rate capability, low in material cost and simple in preparation process, and more has feasibility in large-scale application and industrialization production in the supercapacitor.