The carbide is a promising candidate material for the flexible wearable sensor to monitor the changes from body organs in our daily life. The unique structure of the carbide is a significant factor leading to the sensitivity and stability of the sensor. Here, to imitate the natural three-dimensional (3D) biomass materials, we propose a simple and scalable method to prepare Mo2C–C 3D quasi-sphere architectures using freeze drying and tube furnace heating. The Mo2C–C flexible sensor displays good sensitivity and stability in the multimode movement actions including bend-flat and reverse-flat. The response time of the sensor is as short as 100 ms; and after 400 times test, the signal is still easily recognized. The improved performance originates from the architectures of Mo2C–C 3D quasi-sphere with nanosheets tangle which enhancing conductivity of quasi-spheres during deformation process. Furthermore, the Mo2C–C flexible sensor is practically applied to the fingers to monitor the different finger motions, exhibiting the good potential in biomonitoring devices.