Thermal-based microparticle focusing has recently received increasing attention due to its non-invasive nature and simple manipulation mechanism. However, its further application is limited by current complicated fluid heating systems and low particle focusing velocity. Using simple Indium Tin Oxide-made microheaters, herein we propose a flexible and novel approach for efficient particle focusing based on direct current induced thermal buoyancy convection. Importantly, for avoiding the possible electrochemical reactions on electrode, the microheaters are isolated from the granular fluids of interest by a thin glass slide. The concentration performance of designed chip was firstly demonstrated by statically focusing 4-µm silica particles, yeast cells, silica particles in insulating buffer, and 100-nm copper micro-spheres. Also the trapping of a mixture of 5-µm and 2-µm Poly Styrene microbeads indicated that the chip can either simultaneously con-centrate two kinds of particles or selectively focus the heavier ones by adjusting the voltages. Then the different concentration patterns of microbeads exhibited that the microspheres can be flexibly manipulated by changing the configurations of microheaters. Furthermore, for the first time, we achieved thermal-based continuous particle focusing in both conducting and insulating solutions using buoyancy con-vection, demonstrating that this method can be utilized to achieve both static and continuous particle manipulations in multiple liquid media. Finally, the feasibility of this device in effective wear measurement of machines was demonstrated by conducting systematical experiments of focusing nano-copper particles in the hydraulic oil. Therefore, this presented approach would be promising for a broad range of on-chip applications.