Al2O3-TiO2　hybrid　nanofluids　based　on　DI-water　with　particle　volume　fraction　from　0.1%　to　0.4%　were　prepared　by　the　two-step　methods.　The　appropriate　surfactant　was　added　to　ensure　the　stability　of　hybrid　nanofluids,　and　a　thermal　property　analyzer　(Hot-Disk　2500S)　was　used　to　measure　the　thermal　conductivity　of　hybrid　nanofluids.　The　prepared　hybrid　nanofluids　were　used　to　flow　through　straight-line　and　broken-line　microchannel　heat　sinks,　and　the　effects　of　concentration,　inlet　temperature,　Re　and　microchannel　structure　on　the　heat　transfer　performance　of　microchannels　were　studied.　Results　show　that　compared　with　the　straight-line　microchannels,　the　heat　transfer　performance　of　hybrid　nanofluids　in　the　broken　line　is　more　strengthened;　the　heat　transfer　coefficients　of　hybrid　nanofluids　increase　with　the　increase　of　the　inlet　temperature,Re　and　nanoparticle　volume　fraction;　when　the　inlet　temperature　is　30℃,　and　the　volume　flow　is　30　mL/min,　compared　with　deionized　water,　the　convective　heat　transfer　coefficient,　comprehensive　performance　and　pressure　drop　of　the　hybrid　nanofluids　with　a　volume　fraction　of　0.4%　in　the　broken-line　microchannel　increase　by　30.90%,　18.70%,　and　6.48%,　respectively.　©　2019,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.