Data transmission control method

A transfer control method is provided to enable efficient data transfer when a single optical disk device ( 2 ) is accessed by a plurality of host computers ( 3 ). The method includes: an access position obtaining step of interpreting instructions issued from a plurality of tasks provided on the plurality of host computers ( 3 ) to the optical disk device ( 2 ) and obtaining the access position of data on an optical disk ( 1 ); an access ordering step of generating an access order table for data to be read in sequence, based on the access position obtained at the access position obtaining step; a data storing step of reading the data sequentially according to the access order table generated at the access ordering step and storing the data in a data buffer; and a data transfer step of transferring the data stored in the data buffer to the host computers ( 3 ) in an operation period before the optical disk device ( 2 ) becomes ready to transfer the next data.