Manipulating DNA translocation through nanopore is one crucial requirement for new ultrafast sequencing methods in the sense that the polymers have to be denatured, unraveled, and then propelled through the pore with very low speed. Here we propose and theoretically explore a novel design to fulfill the demands by utilizing cross-pore thermal gradient. The high temperature in the cis reservoir is expected to transform double-stranded DNA into single strands and that temperature would also prevent those single strands from intrastrand base-pairing, thus, achieving favorable polymer conformation for the subsequent translocation and sequencing. Then, the substantial temperature drop across the pore caused by the thermal-insulating membrane separating cis and trans chambers would stimulate thermophoresis of the molecules through nanopores. Our theoretical evaluation shows that the DNA translocation speeds will be orders smaller than the electrophoretic counterpart, while high capture rate of DNA into nanopore is maintained, both of which would greatly benefit the sequencing.