The invention relates to a calcium treatment method of low-carbon low silicon aluminium killed steels under a CSP (Cast Steel Plate) condition, comprising the following steps of: carrying out molten iron pretreatment and rotating furnace smelting; deoxidizing and blowing argon on an argon station; refining: carrying out calcium treatment by adding calcium iron wires step by step and in a transposition way to a steel ladle; continuously blowing the argon; and continuously casting to form a blank. The calcium treatment method disclosed by the invention has the advantages of realizing the stable batched production of the low-carbon low silicon aluminium killed steels, increasing the continuous casting furnaces from original 8 at most to at least 12, obviously reducing the consumption of the calcium iron wires, obviously improving the cleanliness of molten iron and controlling the molten iron T. O and [S] within 20*10-6 when the steel ladle leaves from the argon station.