The rear pressure measurement position of V-cone flowmeter is in the complex vortex structure area after fluid around the cone. The non-uniformity of the fluid field will influence the measurement precision of V-cone flowmeter. Large eddy simulation (LES) has been used to study the V-cone flowmeter’s 3-D flow field structure with different Reynolds number in this paper. The better fluid area information can gain by this way. The results show that the values of discharge coefficient (Cd) obtained from LES are more close to the experiment data than the values obtained from k-ε model. Different turbulence intensity with different Reynolds number effects the velocity distribution in the V-cone flowmeter’s flow field. When Reynolds number equals to 20000, the flow field within 8d distance from V-cone tail should keep from being disturbed while the flowmeter under working condition. The non-interfering distance from V-cone tail flow field increases with the Reynolds number raising. These analysis results can offer optimizational information for V-cone flowmeter performance and testing method improvement.