1D metal‐oxide nanotube (NT) structures have attracted considerable attention for applications in chemical sensors due to their high surface area and unique chemical and physical properties. Moreover, bimodal pores, i.e., meso‐ and macro‐sized pores, which are formed on the shell of NTs, can further facilitate gas penetration into the sensing layers, leading to much improved sensing properties. However, thin‐walled NTs with bimodal pore distribution have been rarely fabricated due to the limitations of synthetic methods. Here, Ostwald ripening‐driven electrospinning combined with sacrificial templating route using polystyrene (PS) colloid and bioinspired protein is firstly proposed for producing both bi‐modal pores and catalyst‐loaded thin‐walled SnO2 NTs. Homogeneous catalyst loading on porous SnO2 NTs is achieved by the protein cage that contains catalysts and PS colloids and protein shells are thermally decomposed during calcination of electrospun fibers, resulting in the creation of dual‐sized pores on NTs. Pt catalyst decorated porous SnO2 NTs (Pt‐PS_SnO2 NTs) show exceptionally high acetone gas response, superior selectivity against other interfering gases, and very low limit of detection (10 ppb) to simulated diabetic acetone molecules. More importantly, sensor arrays assembled with developed porous SnO2 NTs enable the direct distinction between the simulated diabetic breath and normal breath from healthy people. Highly mesoporous SnO2 nanotubes (NTs) functionalized with large pores and bioinspired catalysts (Pt‐PS_SnO2 NTs) are simply synthesized as an ideal nanostructure of sensing layers by using biotemplating route and diffusion of SnO2 effect. Pt‐PS_SnO2 NTs exhibit dramatically enhanced acetone sensing performance; especially, they can clearly distinguish the exhaled breath of healthy people and diabetics.