Molten　salt　reactor　(MSR)　adopts　molten　fluoride　salt　mixture　as　fuel　and　coolant,　and　the　features　of　neutronics　and　thermal-hydraulics　of　MSR　are　different　from　those　of　traditional　solid-fuel　reactors　due　to　flowing　fuel.　Steady　state　analysis　of　a　preliminary　design　of　thorium　molten　salt　reactor　(TMSR)　was　performed　based　on　MSR　analysis　code　MOREL2.0.　The　results　show　that　fuel　flow　brings　a　significant　influence　on　the　distribution　of　delayed　neutron　precursors　and　leads　to　169　pcm　of　reactivity　loss,　keff　decreases　as　the　increase　of　time　spent　through　external　loop　and　tends　to　be　stable　after　80　s,　and　TMSR　has　a　negative　inlet　fuel　temperature　coefficient　and　inherent　safety　characteristic.　©　2018,　Editorial　Board　of　Atomic　Energy　Science　and　Technology.　All　right　reserved.