To solve the difficulty with utilization of maize straw root， the technology of biochar preparation from maize straw root and the biochar properties are analyzed. First， biochar was prepared with the husk， flesh and root of maize straw separately at 300℃/45min， 500℃/30min and 700℃/15min through the sealed oxygen-limiting method. Then， the biochar properties were analyzed， including analyses of the char yield， pH， ash content， infrared spectroscopy， and scanning electron microscopy. The results showed that the carbon yield decreases with temperature， the loss rate of pyrolysis weight increases first and then decreases， and the pH value increases in the range from 300℃ to 700℃； in addition， the characteristic absorption peaks of biochar are basically the same， represented as the total surface functional groups decrease， the acidic functional groups decrease， and the basic functional groups increase. In a word， straw root biochar is similar in functionality to straw pith and straw bark biochar materials. Therefore， the results of this study can be used as theoretical basis and technical support for the resource utilization of maize straw.