Nowadays, two-dimensional transition metal chalcogenides have become attractive materials for flexible wearable devices because of their intriguing chemistry characteristics and sensitivity to external stimuli. However, the growth of two-dimensional materials on polymer surfaces is generally carried out by the time-consuming and costly chemical vapor deposition method. Reducing the manufacturing and integration costs while improving the device performance remains to be challenging. Herein, we report a simple liquid metal-assisted hydrothermal method for the growth of two-dimensional nanomaterials on the polymer surface. Specifically, a layer of liquid metal was coated on commercial tape, while layered cobalt sulfide was grown on its surface by a simple one-step hydrothermal method. Different kinds of flexible sensors can be prepared, such as bending sensor, pressure sensor, and humidity sensor, which can be used to detect motion, writing, breathing, and other signals. This strategy can also be assigned to sensing signals on different objects, which may further expand and enrich the application of two-dimensional materials in sensing.