The dimethyl ether to olefins process is very important for converting coal to chemicals. A SAPO-34 molecular sieve with a particle size up to 50 mu m has been synthesized with morpholine as the template. The cold model fluidization experiment indicates that the SAPO-34 catalyst with average size of 45-50 mu m is of good fluidization properties. After high temperature steam treatment at 1073 K for 8 h, this large fluidizable catalyst showed good reactivity and selectivity for the dimethyl ether to olefins (DTO) reaction in a micro-reactor. X-ray diffraction characterization showed that the structure of the catalyst was maintained well. A fluidized reactor of 50 mm inner diameter was used to carry out the DTO reaction, which showed that the fluidizable SAPO-34 is a selective catalyst for light olefin production.