Flexible pressure sensors as wearable electronic devices to monitor human health have attracted significant attention. Herein, a simple and effective carbonization-free method is proposed to prepare a compressible and conductive reduced graphene oxide (rGO)–modified plant fiber sponge (defined as rGO-PFS). The introduced GO can not only coat on the surface of plant fibers, but also form a large amount of aerogel with microcellular structure in the macroporous PFS. After reduction treatment, the rGO-PFS can form a double-continuous conductive network of rGO aerogel. With the improvement of polydimethylsiloxane (PDMS), the rGO-PFS@PDMS composite exhibits outstanding compressibility (up to 60% compression strain), excellent durability (10,000 stable compression cycles at 50% strain), high sensitivity (234.07 kPa−1 in a pressure range of 20 ~ 387.2 Pa), low detection limit (20 Pa), and rapid response time (28 ms) for practical wearable applications. Graphical Abstract: A compressible and conductive reduced graphene oxide–modified plant fiber sponge is prepared by a simple and effective carbonization-free method. With the improvement of polydimethylsiloxane, the sponge exhibits outstanding compressibility, durability, high sensitivity, low detection limit, and rapid response time for practical wearable applications.