The present invention discloses a detection circuit and a detection method of a self-capacitance touch screen. The detection circuit comprises a charging module and a voltage measuring module. The charging module is employed to connect the at least one touch control line for respectively charging a parasitic capacitance constructed by the at least one corresponding sensing electrode corresponded with the at least one touch control line and a ground by the charging module via the at least one touch control line at the same time in one detection period; the voltage measuring module is employed to electrically connect the at least one touch control line sequentially for acquiring a voltage measured value of the parasitic capacitance after charging via the at least one touch control line and outputting the voltage measured value, to obtain a detection result of normal or fault of the corresponding sensing electrode according to the voltage measured value after the charging module accomplishes charging and is disconnected from the at least one touch control line. With the aforementioned arrangement, the present is capable of simply and effectively achieving the detection of sensing electrodes.