Methanol to olefins (MTO) is an attractive technique. In order to optimize the hydrodynamics of gas-solid phase and the olefins yield and selectivity, a novel MTO high-speed loop reactor (HSLR) is developed. The gas hydrodynamics of bypassing, backmixing and average residence time are explored in a large scale cold model setup. In addition, comparison between the gas backmixing as well as gas residence time in the HSLR and that in the traditional non-draft-tube fluidized bed or free fluidized bed (FFB) is made. Experimental results show that the gas bypassing fractions are closely related to the gas velocity. Based on the axial profiles of Dga and Peclet number, the gas backmixing in the HSLR is much lower than that in the FFB. Moreover, the average gas residence time in the HSLR is considerably short, indicating distinct transport capacity of gas. Furthermore, the proper operating conditions in the HSLR are given. (C) 2019 Published by Elsevier B.V.