The calculation methods of skeleton curve of equal sectional CFST (concrete filled steel tube) columns with flat or inclined lacing tubes were introduced and analyzed. It's found the seismic behavior of equal sectional CFST columns has generality, no matter their lacing tubes are flat or inclined. To find out a uniform calculation method of skeleton curve of equal sectional CFST columns on the base of hysteretic model of CFST single tube column, we explored the calculation methods of elastic stiffness, horizontal peak load, peak load displacement and fall-period stiffness, and then carried out a verification experiment with OpenSEES program by taking the laced column pier of Ganhaizi bridge as an example. Research results indicate that the calculated values of the new calculation method are coincident well with the test and the numerical results. Finally the uniform method which can be adapted to engineering application is provided, and it can provide references for the calculation theory and relevant criteria of CFST structures.