可以使get_legend_handles_labels()方法，不用自己记录lines 和labels。 import numpy as np import matplotlib.pyplot as plt from matplotlib import rc rc('mathtext', default='regular') pi = np.pi # fake data time = np.linspace (0, 25, 50) temp = 50 / np.sqrt (2 * pi * 3**2) \ * np.exp (-((time - 13)**2 / (3**2))**2) + 15 Swdown = 400 / np.sqrt (2 * pi * 3**2) * np.exp (-((time - 13)**2 / (3**2))**2) Rn = Swdown - 10 fig = plt.figure() ax = fig.add_subplot(111) ax.plot(time, Swdown, '-', label = 'Swdown') ax.plot(time, Rn, '-', label = 'Rn') ax2 = ax.twinx() ax2.plot(time, temp, '-r', label = 'temp') # ask matplotlib for the plotted objects and their labels lines, labels = ax.get_legend_handles_labels() lines2, labels2 = ax2.get_legend_handles_labels() ax2.legend(lines + lines2, labels + labels2, loc=0) ax.grid() ax.set_xlabel("Time (h)") ax.set_ylabel(r"Radiation ($MJ\,m^{-2}\,d^{-1}$)") ax2.set_ylabel(r"Temperature ($^\circ$C)") ax2.set_ylim(0, 35) ax.set_ylim(-20,100) plt.show()... 展开详请