The invention provides a differential new user selection 
access method applicable to a non-orthogonal multi-access 
system, and relates to differential new user selection 
access technology applicable to non-orthogonal multi-access systems. The differential new user selection 
access method is used for enabling new users in the non-orthogonal multi-access 
system to better access the network. The method comprises the following steps: a first step, establishing an 
information resource pool of a full-band candidate user set; a second step, selecting sub-bands which satisfy bandwidth requirements; a third step, sequentially calculating differences of 
signal to interference plus 
noise power ratios; a fourth step, calculating a ratio A<l> of the number of users, satisfying preset standards, of each sub-band to the total number of candidate users of the sub-band, and sorting the ratios A<l> from small to large; a fifth step, carrying out selection according to the expression described in the specification; and a sixth step, carrying out non-orthogonal coding on the new access 
user information and other candidate 
user information through 
superposition coding, and conducting 
signal transmission. The differential new user selection 
access method provided by the invention is applicable to the differential new user selection access of the non-orthogonal multi-access 
system, and can satisfy the demand of a 5G new user access solution in the future.