Preparation for binary magnetic fluid

The invention relates to a manufacturing method for binary magnetic liquid, which comprises the following steps; firstly, ferrimagnetic nanoparticle with ferromagnetism, which is particle A, and weak magnetic paramagnetic nanoparticle, which is particle B, are produced respectively by a method of chemical coprecipitation, so that two nanoparticles with different magnetism are produced; secondly, the particle A and the particle B are made into ferromagnetic liquid A and paramagnetic liquid B having the same volume fraction phiA equaling phiB equaling phi0 with Q value within the range of 0.12-0.20 respectively by a Massart method; thirdly, liquid A and liquid B are mixed into a binary magnetic liquid. In the binary ionic magnetic liquid, field structure and field physical effects mainly originate from the ferromagnetic part, and weak magnetic part can generate modulation effect.