The invention relates to a rail allotype high capacity tank car transport liquid iron system and technics, which is suitable for liquid iron transport among iron and steel in large-size steel plant. The utility model is characterized in that: firstly, a liquid iron transport line and a steel-making workshop are laid in parallel; secondly, a blast furnace and the steel-making workshop are laid closely, the straight line distance is 900 to 1000 meters; thirdly, a liquid tank car for transporting liquid iron is arranged between the blast furnace and the steel-making workshop; fourthly, a test tank chamber is arranged between the steel-making workshop and a liquid railway switchyard; fifthly, a measurement device for continuous weighting is arranged on the orbit at the position of receiving iron in iron producing plant; sixthly, an intelligent transport dispatch system is provided. The invention overcomes the problem that the traditional rail allotype liquid iron transport has multiple sections, low production efficiency, large heat consumption, high energy consumption, poor three-slipping effect, large one-time investment, high running cost and poor environment condition.