***UPDATE: According to the original info pointed out by Troy Teslike, Industrial Securities estimates the expected volume in early 2021, not the current production volume.
That's a lot, about 400,000 per year, including roughly 250,000 Model 3 and roughly 150,000 Model Y. Moreover, the same source forecasts that by the end of the year, Tesla will gradually increase the rate to 15,000 per week (or roughly 750,000 per year).
Well, the official info from October was that the Giga Shanghai will initially be at 150,000 Model Y, while the Model 3 is at up to 250,000, so we know that 500,000 a year (2x 250,000) is possible.
Anyway, the forecast is that in 2021 Tesla will sell in China 425,000 MIC cars (180,000 Model 3, 245,000 Model Y) and export an additional 100,000 Model 3/Y.
That would mean production of around 525,000 - more than in all of 2020 by two plants (in California and China). It's expected that all the locally made Model Y will be sold in China, so the export concerns only Model 3.