Hydrogen sensors offer a promising technology for inchoate warning of lithium battery thermal runaway. However, further exploration is still needed to enhance their gas-sensing properties. In this study, Co
3
O
4
dodecahedrons and Pd nanoparticles-embedded In
2
O
3
microtubes were synthesized using the MIL-68@ZIF-67 template and chemical reduction method. As a result, Co
3
O
4
dodecahedrons are equably anchored on the
In
2
O
3
microtubes, and Pd nanoparticles with different contents are loaded on the In
2
O
3
@Co
3
O
4
, forming In
2
O
3
@Co
3
O
4
@Pd composite microtubes. The sensor based on In
2
O
3
@Co
3
O
4
@Pd with a Pd loading of 0.40 wt% achieves a response of 4.47 and 2.85 toward 20 H
2
at 210
◦
C and 80
◦
C, respectively, whereas the sensors based on bare In
2
O
3
and In
2
O
3
@Co
3
O
4
are unresponsive at these two temperatures. Moreover, fast response time (4.5 s), good selectivity and reproducibility, as well as a wide concentration detection range (0.5
–
1000 ppm) are also obtained. The one-dimensional (1D) microstructure with a high length-to-diameter ratio affords abundant tightly connected n-p heterojunctions between In
2
O
3
and Co
3
O
4
, and the intense interaction between Pd and In
2
O
3
@Co
3
O
4
increases the content of oxygen vacancies, which jointly boost the H
2
-sensing properties. The obtained In
2
O
3
@Co
3
O
4
@Pd composite has a promising application in real-time H
2
detection.
