In order to broaden the application range of magnesium oxychloride cement (MOC), the effects of three retarders including citric acid, boric acid and sodium gluconate on the setting time, compressive strength, electrical resistivity, heat of hydration and water resistance of magnesium oxychloride cement were investigated. Meanwhile, X-ray diffractometer was used to analyze the hydration products of modified MOC. The results show that retarders prolong the setting time. When the content of retarders is 0.75% (mass fraction, the same below), the 28 d compressive strength of samples compared with the control group decreases by 19.3%, 16.7% and 20.2%, respectively. The addition of retarders reduces the peak value of electrical resistivity rate curves and internal temperature curves, delays the second peak of hydration heat rate curves, that is, retarders reduce the hydration rate of magnesium oxychloride cement so that the heat is liberated slowly. Retarders can improve the water resistance of magnesium oxychloride cement. When the content of boric acid is 0.75%, the softening coefficient reaches 0.79.