With the emergence of environmental problems, the green, degradable, sustainable, and environmentally friendly electronic device has become one of the current research hotspots. In this work, an organic biomemristor device was prepared using the lotus root as a functional layer on a fixable substrate, which shows an excellent memristive memory performance. Further, we studied the effect of acidity and alkalinity (pH) on the memristive performance of the device, in which it can be found that the pH can regulate the memristive behavior and memory window. Moreover, an apparent memristive behavior and stable reading-writing characteristic in neutral condition (pH = 7.0) were observed, and the high-resistance state/low-resistance state resistance ratio under the neutral condition is significantly larger than that under acid and alkali conditions. Therefore, our device can be used in lightweight and portable wearable device. In a word, this research can provide meaningful insights for developing sustainable bioelectronic devices with potential applications in information technology.